THE ACOUSTIC ANALYSIS OF THE OLD SENATE CHAMBER

BY

ODOGUN OLAWOLE STEPHEN

ARC097399

MEKULEYI OLABODE

ARC097396

SUBMITTED TO

THE FEDERAL UNIVERSITY OF TECHNOLOFY AKURE

THE DEPARTMENT OF ARCHITECTURE

COURSE CODE ARC 507

COURSE TITLE ENVIRONMENTAL CONTROL III

(ACOUSTICS AND NOISE CONTROL)

COURSE LECTURER PROF OLU OLA OGUNSOTE

JULY 2014

10 INTRODUCTION 1

20 DESCRIPTION OF THE OLD SENATE CHAMBER 1

21 Location 1

22 Architectural Design of building 2

221 Wall finishes 3

222 Floor finishes 4

223 Ceiling finishes 4

224 Fenestrations 5

225 Furniture 5

30 VIEWS OF THE SEATING ARRANGEMENT 6

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE

OLD SENATE CHAMBER 7

32 SOURCES OF OUTDOOR NOISE 8

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF

THE OLD SENATE CHAMBER 9

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD

SENATE CHAMBER 11

51 REDUCTION OF INTERNAL NOISE 11

52 REDUCTION OF EXTERNAL NOISE 12

60 CONCLUSION 12

70 REFERENCES 13

10 INTRODUCTION

The studying of the acoustic properties of a building is as important as the buildings form itself

function and structure which is defined analyzed and prescribed according to the use to which

the room space or building is put to Various spaces within a building has various purposes ie

living room theatre studio dinning bedroom etc which leads to the acoustic variation within

the spaces but it is treated as one single entity of the total building Acoustic

Paying close attention to the acoustics properties of a particular space before or after construction

is important also in terms of knowing the kind of materials to use on the floor wall furniture

( general finishes) etc in that particular space

20 DESCRIPTION OF THE OLD SENATE CHAMBER

The old senate chamber is a room in the senate building of the federal university of technology

Akure used as the legislative chamber of the university but now old chamber as new one has

been constructed in the senate extension besides the new old senate building The room also

serves as the Supreme Court chamber of the university where various issues are trashed out

21 LOCATION OF THE CHAMBER

The old senate chamber is located at the first floor of the main senate building located at the

center heart of the school in Oba-nla region of the FUTA campus with ldquovehicular circulation

routerdquo from obakekere north gate coming from the Ilesha- Ibadan express way the School of

Environmental technology School of Engineering and Engineering Technology and has its

nearest neighbors to be the Student affairs building- which is directly opposite it the Theodore

Idibiye auditorium bank area motion ground and also the Student union building The

environment is blessed with green vegetation of well-maintained grasses flowers etc

pg 1

22 ARCHITECTURAL DESIGN HISTORY OF FUTA SENATE BUILDING

The buildingrsquos design aligns with the contemporary trend of architecture as it embodies the

salient elements of architectural design in this modern era even though itrsquos not a twenty first

century building These governing elements span from materials of construction to type and

property of finishes etc used in the design The building is predominantly the most Important

building in the university as all major decisions are made in the building and the building also

houses some of the most important personality of the university ranging from the vice

chancellor deputy vice chancellor and a host of notable offices like admission office

examination office to mention a few The building has 3 floors and a pent floor that makes it 4

floors and has a massive car parking opposite it plus its extension seating directly beside it

For the purpose of the Couse we will be concentrating on the first floor which is the section of

the senate building that houses the old senate chamber Acoustics properties of the room (interior

and exterior) will be considered particularly the materials finishes of the interior wall and

exterior wall floor finishes ceiling finishes etc

FLOORPLAN AND OF THE OLD

SENATE CHAMBER (INTERNAL)

pg 2

PLATE 1

Wooden furnitures

SITE PLAN SHOWING EXTERNAL SOURCES OF NOISE

221 WALL FINISHES

The walls fall into two categories the interior walls and the exterior walls The interiors walls

are designed with hollow sand-crete blocks with a layer of mortar plastering which is finished

with coating of light coloured cream emulsion paints The acoustic property of sand-crete blocks

rendered with cement plaster has a pretty low absorption co-efficient

The exterior walls are also constructed with sand-crete blocks with a layer of mortar screed and

they are finished with textcoat paints which are also light coloured cream The roughness the

pg 3

PLATE 2

surface improves its acoustic quality because Rough walls tend to diffuse sound reflecting it in

a variety of directions Hence very little sound can be absorbed from out noise sources and

transmitted into the building and coupled with the fact that itrsquos almost a secluded area with little

movement around without a real purpose

222 FLOOR FINISHES

The floors of the spaces in the buildings are finished with deep polished terrazzo floor finish

This is quite poor as an acoustic material since terrazzo has a very low absorption co-efficient

002 at 1000Hz and its smooth nature reflects the sound

undesirably

But with this in mind a correction measure had

already been taking by laying of sound absorbing

material Ie rug and an underlay foam which actually

helps in reducing the echoes or reverberations of

sound whenever the room is put to use

223 CEILING FINISHES

Due to the use at which the room is put to the ceiling was finished with wooden plywood of

600x600mm and a little part finished with concrete slabs with a layer of mortar screed Wood

was used as the ceiling finish because of its acoustics capabilities wood produces sound by

direct striking and can amplify or absorb sound waves

originating from other bodies For these reasons itrsquos a

unique material for musical instruments and other

acoustics applications like that itrsquos used for at the old

senate chamber because when sound waves of extrinsic

origin strike wood they partly absorbed and partly

pg 4

PLATE 4

PLATE 3

reflected and the wood is set in vibration

NOTE normally wood absorbs a very small portion of acoustic energy (3-5percent) but

special constructions incorporating empty spaces and porous insulation boards can

increase absorption to as high as 90percent

224 FENESTRATIONS

The amount of openings in a space is referred to as Fenestration It is a critical feature in

acoustic considerations in buildings The shape type and size of the fenestrations are parameters

that shouldnrsquot be undermined in takingnoting architectural acoustics The windows in the old

senate chamber are made from glass and they are fixed type The windows are of 300mm height

but span the whole of the room at the bottom and top side of the room with the only movable

window been the windows at the podium of the chamber which are often locked as well They

are framed with aluminum mullions The two doors in the chamber are also made of tempered

glass of between 8mm-10mm thick glass framed with aluminum mullions and are all double leaf

swing doors of 900 x 2100mm per leaf

The windows are predominantly used for lighting but not

for ventilation purposes as the major ventilation in the chamber

are artificial hence they are always left locked The closed

window then disallows and reduces external noise to

Impinge the internal spaces

225 FURNITURE

The furniture in the spaces under consideration goes with the use The basic furniture types are

the plywood drawing boards there are also wooded chairs with cloth cladding and heavy timber

deskscabinets Wood generally is a good absorber of sound but that is not enough to improve the

acoustics of the room to an appreciable level also The acoustics of the chamber may be very

pg 5

PLATE 5

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

10 INTRODUCTION 1

20 DESCRIPTION OF THE OLD SENATE CHAMBER 1

21 Location 1

22 Architectural Design of building 2

221 Wall finishes 3

222 Floor finishes 4

223 Ceiling finishes 4

224 Fenestrations 5

225 Furniture 5

30 VIEWS OF THE SEATING ARRANGEMENT 6

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE

OLD SENATE CHAMBER 7

32 SOURCES OF OUTDOOR NOISE 8

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF

THE OLD SENATE CHAMBER 9

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD

SENATE CHAMBER 11

51 REDUCTION OF INTERNAL NOISE 11

52 REDUCTION OF EXTERNAL NOISE 12

60 CONCLUSION 12

70 REFERENCES 13

10 INTRODUCTION

The studying of the acoustic properties of a building is as important as the buildings form itself

function and structure which is defined analyzed and prescribed according to the use to which

the room space or building is put to Various spaces within a building has various purposes ie

living room theatre studio dinning bedroom etc which leads to the acoustic variation within

the spaces but it is treated as one single entity of the total building Acoustic

Paying close attention to the acoustics properties of a particular space before or after construction

is important also in terms of knowing the kind of materials to use on the floor wall furniture

( general finishes) etc in that particular space

20 DESCRIPTION OF THE OLD SENATE CHAMBER

The old senate chamber is a room in the senate building of the federal university of technology

Akure used as the legislative chamber of the university but now old chamber as new one has

been constructed in the senate extension besides the new old senate building The room also

serves as the Supreme Court chamber of the university where various issues are trashed out

21 LOCATION OF THE CHAMBER

The old senate chamber is located at the first floor of the main senate building located at the

center heart of the school in Oba-nla region of the FUTA campus with ldquovehicular circulation

routerdquo from obakekere north gate coming from the Ilesha- Ibadan express way the School of

Environmental technology School of Engineering and Engineering Technology and has its

nearest neighbors to be the Student affairs building- which is directly opposite it the Theodore

Idibiye auditorium bank area motion ground and also the Student union building The

environment is blessed with green vegetation of well-maintained grasses flowers etc

pg 1

22 ARCHITECTURAL DESIGN HISTORY OF FUTA SENATE BUILDING

The buildingrsquos design aligns with the contemporary trend of architecture as it embodies the

salient elements of architectural design in this modern era even though itrsquos not a twenty first

century building These governing elements span from materials of construction to type and

property of finishes etc used in the design The building is predominantly the most Important

building in the university as all major decisions are made in the building and the building also

houses some of the most important personality of the university ranging from the vice

chancellor deputy vice chancellor and a host of notable offices like admission office

examination office to mention a few The building has 3 floors and a pent floor that makes it 4

floors and has a massive car parking opposite it plus its extension seating directly beside it

For the purpose of the Couse we will be concentrating on the first floor which is the section of

the senate building that houses the old senate chamber Acoustics properties of the room (interior

and exterior) will be considered particularly the materials finishes of the interior wall and

exterior wall floor finishes ceiling finishes etc

FLOORPLAN AND OF THE OLD

SENATE CHAMBER (INTERNAL)

pg 2

PLATE 1

Wooden furnitures

SITE PLAN SHOWING EXTERNAL SOURCES OF NOISE

221 WALL FINISHES

The walls fall into two categories the interior walls and the exterior walls The interiors walls

are designed with hollow sand-crete blocks with a layer of mortar plastering which is finished

with coating of light coloured cream emulsion paints The acoustic property of sand-crete blocks

rendered with cement plaster has a pretty low absorption co-efficient

The exterior walls are also constructed with sand-crete blocks with a layer of mortar screed and

they are finished with textcoat paints which are also light coloured cream The roughness the

pg 3

PLATE 2

surface improves its acoustic quality because Rough walls tend to diffuse sound reflecting it in

a variety of directions Hence very little sound can be absorbed from out noise sources and

transmitted into the building and coupled with the fact that itrsquos almost a secluded area with little

movement around without a real purpose

222 FLOOR FINISHES

The floors of the spaces in the buildings are finished with deep polished terrazzo floor finish

This is quite poor as an acoustic material since terrazzo has a very low absorption co-efficient

002 at 1000Hz and its smooth nature reflects the sound

undesirably

But with this in mind a correction measure had

already been taking by laying of sound absorbing

material Ie rug and an underlay foam which actually

helps in reducing the echoes or reverberations of

sound whenever the room is put to use

223 CEILING FINISHES

Due to the use at which the room is put to the ceiling was finished with wooden plywood of

600x600mm and a little part finished with concrete slabs with a layer of mortar screed Wood

was used as the ceiling finish because of its acoustics capabilities wood produces sound by

direct striking and can amplify or absorb sound waves

originating from other bodies For these reasons itrsquos a

unique material for musical instruments and other

acoustics applications like that itrsquos used for at the old

senate chamber because when sound waves of extrinsic

origin strike wood they partly absorbed and partly

pg 4

PLATE 4

PLATE 3

reflected and the wood is set in vibration

NOTE normally wood absorbs a very small portion of acoustic energy (3-5percent) but

special constructions incorporating empty spaces and porous insulation boards can

increase absorption to as high as 90percent

224 FENESTRATIONS

The amount of openings in a space is referred to as Fenestration It is a critical feature in

acoustic considerations in buildings The shape type and size of the fenestrations are parameters

that shouldnrsquot be undermined in takingnoting architectural acoustics The windows in the old

senate chamber are made from glass and they are fixed type The windows are of 300mm height

but span the whole of the room at the bottom and top side of the room with the only movable

window been the windows at the podium of the chamber which are often locked as well They

are framed with aluminum mullions The two doors in the chamber are also made of tempered

glass of between 8mm-10mm thick glass framed with aluminum mullions and are all double leaf

swing doors of 900 x 2100mm per leaf

The windows are predominantly used for lighting but not

for ventilation purposes as the major ventilation in the chamber

are artificial hence they are always left locked The closed

window then disallows and reduces external noise to

Impinge the internal spaces

225 FURNITURE

The furniture in the spaces under consideration goes with the use The basic furniture types are

the plywood drawing boards there are also wooded chairs with cloth cladding and heavy timber

deskscabinets Wood generally is a good absorber of sound but that is not enough to improve the

acoustics of the room to an appreciable level also The acoustics of the chamber may be very

pg 5

PLATE 5

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

10 INTRODUCTION

The studying of the acoustic properties of a building is as important as the buildings form itself

function and structure which is defined analyzed and prescribed according to the use to which

the room space or building is put to Various spaces within a building has various purposes ie

living room theatre studio dinning bedroom etc which leads to the acoustic variation within

the spaces but it is treated as one single entity of the total building Acoustic

Paying close attention to the acoustics properties of a particular space before or after construction

is important also in terms of knowing the kind of materials to use on the floor wall furniture

( general finishes) etc in that particular space

20 DESCRIPTION OF THE OLD SENATE CHAMBER

The old senate chamber is a room in the senate building of the federal university of technology

Akure used as the legislative chamber of the university but now old chamber as new one has

been constructed in the senate extension besides the new old senate building The room also

serves as the Supreme Court chamber of the university where various issues are trashed out

21 LOCATION OF THE CHAMBER

The old senate chamber is located at the first floor of the main senate building located at the

center heart of the school in Oba-nla region of the FUTA campus with ldquovehicular circulation

routerdquo from obakekere north gate coming from the Ilesha- Ibadan express way the School of

Environmental technology School of Engineering and Engineering Technology and has its

nearest neighbors to be the Student affairs building- which is directly opposite it the Theodore

Idibiye auditorium bank area motion ground and also the Student union building The

environment is blessed with green vegetation of well-maintained grasses flowers etc

pg 1

22 ARCHITECTURAL DESIGN HISTORY OF FUTA SENATE BUILDING

The buildingrsquos design aligns with the contemporary trend of architecture as it embodies the

salient elements of architectural design in this modern era even though itrsquos not a twenty first

century building These governing elements span from materials of construction to type and

property of finishes etc used in the design The building is predominantly the most Important

building in the university as all major decisions are made in the building and the building also

houses some of the most important personality of the university ranging from the vice

chancellor deputy vice chancellor and a host of notable offices like admission office

examination office to mention a few The building has 3 floors and a pent floor that makes it 4

floors and has a massive car parking opposite it plus its extension seating directly beside it

For the purpose of the Couse we will be concentrating on the first floor which is the section of

the senate building that houses the old senate chamber Acoustics properties of the room (interior

and exterior) will be considered particularly the materials finishes of the interior wall and

exterior wall floor finishes ceiling finishes etc

FLOORPLAN AND OF THE OLD

SENATE CHAMBER (INTERNAL)

pg 2

PLATE 1

Wooden furnitures

SITE PLAN SHOWING EXTERNAL SOURCES OF NOISE

221 WALL FINISHES

The walls fall into two categories the interior walls and the exterior walls The interiors walls

are designed with hollow sand-crete blocks with a layer of mortar plastering which is finished

with coating of light coloured cream emulsion paints The acoustic property of sand-crete blocks

rendered with cement plaster has a pretty low absorption co-efficient

The exterior walls are also constructed with sand-crete blocks with a layer of mortar screed and

they are finished with textcoat paints which are also light coloured cream The roughness the

pg 3

PLATE 2

surface improves its acoustic quality because Rough walls tend to diffuse sound reflecting it in

a variety of directions Hence very little sound can be absorbed from out noise sources and

transmitted into the building and coupled with the fact that itrsquos almost a secluded area with little

movement around without a real purpose

222 FLOOR FINISHES

The floors of the spaces in the buildings are finished with deep polished terrazzo floor finish

This is quite poor as an acoustic material since terrazzo has a very low absorption co-efficient

002 at 1000Hz and its smooth nature reflects the sound

undesirably

But with this in mind a correction measure had

already been taking by laying of sound absorbing

material Ie rug and an underlay foam which actually

helps in reducing the echoes or reverberations of

sound whenever the room is put to use

223 CEILING FINISHES

Due to the use at which the room is put to the ceiling was finished with wooden plywood of

600x600mm and a little part finished with concrete slabs with a layer of mortar screed Wood

was used as the ceiling finish because of its acoustics capabilities wood produces sound by

direct striking and can amplify or absorb sound waves

originating from other bodies For these reasons itrsquos a

unique material for musical instruments and other

acoustics applications like that itrsquos used for at the old

senate chamber because when sound waves of extrinsic

origin strike wood they partly absorbed and partly

pg 4

PLATE 4

PLATE 3

reflected and the wood is set in vibration

NOTE normally wood absorbs a very small portion of acoustic energy (3-5percent) but

special constructions incorporating empty spaces and porous insulation boards can

increase absorption to as high as 90percent

224 FENESTRATIONS

The amount of openings in a space is referred to as Fenestration It is a critical feature in

acoustic considerations in buildings The shape type and size of the fenestrations are parameters

that shouldnrsquot be undermined in takingnoting architectural acoustics The windows in the old

senate chamber are made from glass and they are fixed type The windows are of 300mm height

but span the whole of the room at the bottom and top side of the room with the only movable

window been the windows at the podium of the chamber which are often locked as well They

are framed with aluminum mullions The two doors in the chamber are also made of tempered

glass of between 8mm-10mm thick glass framed with aluminum mullions and are all double leaf

swing doors of 900 x 2100mm per leaf

The windows are predominantly used for lighting but not

for ventilation purposes as the major ventilation in the chamber

are artificial hence they are always left locked The closed

window then disallows and reduces external noise to

Impinge the internal spaces

225 FURNITURE

The furniture in the spaces under consideration goes with the use The basic furniture types are

the plywood drawing boards there are also wooded chairs with cloth cladding and heavy timber

deskscabinets Wood generally is a good absorber of sound but that is not enough to improve the

acoustics of the room to an appreciable level also The acoustics of the chamber may be very

pg 5

PLATE 5

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

22 ARCHITECTURAL DESIGN HISTORY OF FUTA SENATE BUILDING

The buildingrsquos design aligns with the contemporary trend of architecture as it embodies the

salient elements of architectural design in this modern era even though itrsquos not a twenty first

century building These governing elements span from materials of construction to type and

property of finishes etc used in the design The building is predominantly the most Important

building in the university as all major decisions are made in the building and the building also

houses some of the most important personality of the university ranging from the vice

chancellor deputy vice chancellor and a host of notable offices like admission office

examination office to mention a few The building has 3 floors and a pent floor that makes it 4

floors and has a massive car parking opposite it plus its extension seating directly beside it

For the purpose of the Couse we will be concentrating on the first floor which is the section of

the senate building that houses the old senate chamber Acoustics properties of the room (interior

and exterior) will be considered particularly the materials finishes of the interior wall and

exterior wall floor finishes ceiling finishes etc

FLOORPLAN AND OF THE OLD

SENATE CHAMBER (INTERNAL)

pg 2

PLATE 1

Wooden furnitures

SITE PLAN SHOWING EXTERNAL SOURCES OF NOISE

221 WALL FINISHES

The walls fall into two categories the interior walls and the exterior walls The interiors walls

are designed with hollow sand-crete blocks with a layer of mortar plastering which is finished

with coating of light coloured cream emulsion paints The acoustic property of sand-crete blocks

rendered with cement plaster has a pretty low absorption co-efficient

The exterior walls are also constructed with sand-crete blocks with a layer of mortar screed and

they are finished with textcoat paints which are also light coloured cream The roughness the

pg 3

PLATE 2

surface improves its acoustic quality because Rough walls tend to diffuse sound reflecting it in

a variety of directions Hence very little sound can be absorbed from out noise sources and

transmitted into the building and coupled with the fact that itrsquos almost a secluded area with little

movement around without a real purpose

222 FLOOR FINISHES

The floors of the spaces in the buildings are finished with deep polished terrazzo floor finish

This is quite poor as an acoustic material since terrazzo has a very low absorption co-efficient

002 at 1000Hz and its smooth nature reflects the sound

undesirably

But with this in mind a correction measure had

already been taking by laying of sound absorbing

material Ie rug and an underlay foam which actually

helps in reducing the echoes or reverberations of

sound whenever the room is put to use

223 CEILING FINISHES

Due to the use at which the room is put to the ceiling was finished with wooden plywood of

600x600mm and a little part finished with concrete slabs with a layer of mortar screed Wood

was used as the ceiling finish because of its acoustics capabilities wood produces sound by

direct striking and can amplify or absorb sound waves

originating from other bodies For these reasons itrsquos a

unique material for musical instruments and other

acoustics applications like that itrsquos used for at the old

senate chamber because when sound waves of extrinsic

origin strike wood they partly absorbed and partly

pg 4

PLATE 4

PLATE 3

reflected and the wood is set in vibration

NOTE normally wood absorbs a very small portion of acoustic energy (3-5percent) but

special constructions incorporating empty spaces and porous insulation boards can

increase absorption to as high as 90percent

224 FENESTRATIONS

The amount of openings in a space is referred to as Fenestration It is a critical feature in

acoustic considerations in buildings The shape type and size of the fenestrations are parameters

that shouldnrsquot be undermined in takingnoting architectural acoustics The windows in the old

senate chamber are made from glass and they are fixed type The windows are of 300mm height

but span the whole of the room at the bottom and top side of the room with the only movable

window been the windows at the podium of the chamber which are often locked as well They

are framed with aluminum mullions The two doors in the chamber are also made of tempered

glass of between 8mm-10mm thick glass framed with aluminum mullions and are all double leaf

swing doors of 900 x 2100mm per leaf

The windows are predominantly used for lighting but not

for ventilation purposes as the major ventilation in the chamber

are artificial hence they are always left locked The closed

window then disallows and reduces external noise to

Impinge the internal spaces

225 FURNITURE

The furniture in the spaces under consideration goes with the use The basic furniture types are

the plywood drawing boards there are also wooded chairs with cloth cladding and heavy timber

deskscabinets Wood generally is a good absorber of sound but that is not enough to improve the

acoustics of the room to an appreciable level also The acoustics of the chamber may be very

pg 5

PLATE 5

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

SITE PLAN SHOWING EXTERNAL SOURCES OF NOISE

221 WALL FINISHES

The walls fall into two categories the interior walls and the exterior walls The interiors walls

are designed with hollow sand-crete blocks with a layer of mortar plastering which is finished

with coating of light coloured cream emulsion paints The acoustic property of sand-crete blocks

rendered with cement plaster has a pretty low absorption co-efficient

The exterior walls are also constructed with sand-crete blocks with a layer of mortar screed and

they are finished with textcoat paints which are also light coloured cream The roughness the

pg 3

PLATE 2

surface improves its acoustic quality because Rough walls tend to diffuse sound reflecting it in

a variety of directions Hence very little sound can be absorbed from out noise sources and

transmitted into the building and coupled with the fact that itrsquos almost a secluded area with little

movement around without a real purpose

222 FLOOR FINISHES

The floors of the spaces in the buildings are finished with deep polished terrazzo floor finish

This is quite poor as an acoustic material since terrazzo has a very low absorption co-efficient

002 at 1000Hz and its smooth nature reflects the sound

undesirably

But with this in mind a correction measure had

already been taking by laying of sound absorbing

material Ie rug and an underlay foam which actually

helps in reducing the echoes or reverberations of

sound whenever the room is put to use

223 CEILING FINISHES

Due to the use at which the room is put to the ceiling was finished with wooden plywood of

600x600mm and a little part finished with concrete slabs with a layer of mortar screed Wood

was used as the ceiling finish because of its acoustics capabilities wood produces sound by

direct striking and can amplify or absorb sound waves

originating from other bodies For these reasons itrsquos a

unique material for musical instruments and other

acoustics applications like that itrsquos used for at the old

senate chamber because when sound waves of extrinsic

origin strike wood they partly absorbed and partly

pg 4

PLATE 4

PLATE 3

reflected and the wood is set in vibration

NOTE normally wood absorbs a very small portion of acoustic energy (3-5percent) but

special constructions incorporating empty spaces and porous insulation boards can

increase absorption to as high as 90percent

224 FENESTRATIONS

The amount of openings in a space is referred to as Fenestration It is a critical feature in

acoustic considerations in buildings The shape type and size of the fenestrations are parameters

that shouldnrsquot be undermined in takingnoting architectural acoustics The windows in the old

senate chamber are made from glass and they are fixed type The windows are of 300mm height

but span the whole of the room at the bottom and top side of the room with the only movable

window been the windows at the podium of the chamber which are often locked as well They

are framed with aluminum mullions The two doors in the chamber are also made of tempered

glass of between 8mm-10mm thick glass framed with aluminum mullions and are all double leaf

swing doors of 900 x 2100mm per leaf

The windows are predominantly used for lighting but not

for ventilation purposes as the major ventilation in the chamber

are artificial hence they are always left locked The closed

window then disallows and reduces external noise to

Impinge the internal spaces

225 FURNITURE

The furniture in the spaces under consideration goes with the use The basic furniture types are

the plywood drawing boards there are also wooded chairs with cloth cladding and heavy timber

deskscabinets Wood generally is a good absorber of sound but that is not enough to improve the

acoustics of the room to an appreciable level also The acoustics of the chamber may be very

pg 5

PLATE 5

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

surface improves its acoustic quality because Rough walls tend to diffuse sound reflecting it in

a variety of directions Hence very little sound can be absorbed from out noise sources and

transmitted into the building and coupled with the fact that itrsquos almost a secluded area with little

movement around without a real purpose

222 FLOOR FINISHES

The floors of the spaces in the buildings are finished with deep polished terrazzo floor finish

This is quite poor as an acoustic material since terrazzo has a very low absorption co-efficient

002 at 1000Hz and its smooth nature reflects the sound

undesirably

But with this in mind a correction measure had

already been taking by laying of sound absorbing

material Ie rug and an underlay foam which actually

helps in reducing the echoes or reverberations of

sound whenever the room is put to use

223 CEILING FINISHES

Due to the use at which the room is put to the ceiling was finished with wooden plywood of

600x600mm and a little part finished with concrete slabs with a layer of mortar screed Wood

was used as the ceiling finish because of its acoustics capabilities wood produces sound by

direct striking and can amplify or absorb sound waves

originating from other bodies For these reasons itrsquos a

unique material for musical instruments and other

acoustics applications like that itrsquos used for at the old

senate chamber because when sound waves of extrinsic

origin strike wood they partly absorbed and partly

pg 4

PLATE 4

PLATE 3

reflected and the wood is set in vibration

NOTE normally wood absorbs a very small portion of acoustic energy (3-5percent) but

special constructions incorporating empty spaces and porous insulation boards can

increase absorption to as high as 90percent

224 FENESTRATIONS

The amount of openings in a space is referred to as Fenestration It is a critical feature in

acoustic considerations in buildings The shape type and size of the fenestrations are parameters

that shouldnrsquot be undermined in takingnoting architectural acoustics The windows in the old

senate chamber are made from glass and they are fixed type The windows are of 300mm height

but span the whole of the room at the bottom and top side of the room with the only movable

window been the windows at the podium of the chamber which are often locked as well They

are framed with aluminum mullions The two doors in the chamber are also made of tempered

glass of between 8mm-10mm thick glass framed with aluminum mullions and are all double leaf

swing doors of 900 x 2100mm per leaf

The windows are predominantly used for lighting but not

for ventilation purposes as the major ventilation in the chamber

are artificial hence they are always left locked The closed

window then disallows and reduces external noise to

Impinge the internal spaces

225 FURNITURE

The furniture in the spaces under consideration goes with the use The basic furniture types are

the plywood drawing boards there are also wooded chairs with cloth cladding and heavy timber

deskscabinets Wood generally is a good absorber of sound but that is not enough to improve the

acoustics of the room to an appreciable level also The acoustics of the chamber may be very

pg 5

PLATE 5

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

reflected and the wood is set in vibration

NOTE normally wood absorbs a very small portion of acoustic energy (3-5percent) but

special constructions incorporating empty spaces and porous insulation boards can

increase absorption to as high as 90percent

224 FENESTRATIONS

The amount of openings in a space is referred to as Fenestration It is a critical feature in

acoustic considerations in buildings The shape type and size of the fenestrations are parameters

that shouldnrsquot be undermined in takingnoting architectural acoustics The windows in the old

senate chamber are made from glass and they are fixed type The windows are of 300mm height

but span the whole of the room at the bottom and top side of the room with the only movable

window been the windows at the podium of the chamber which are often locked as well They

are framed with aluminum mullions The two doors in the chamber are also made of tempered

glass of between 8mm-10mm thick glass framed with aluminum mullions and are all double leaf

swing doors of 900 x 2100mm per leaf

The windows are predominantly used for lighting but not

for ventilation purposes as the major ventilation in the chamber

are artificial hence they are always left locked The closed

window then disallows and reduces external noise to

Impinge the internal spaces

225 FURNITURE

The furniture in the spaces under consideration goes with the use The basic furniture types are

the plywood drawing boards there are also wooded chairs with cloth cladding and heavy timber

deskscabinets Wood generally is a good absorber of sound but that is not enough to improve the

acoustics of the room to an appreciable level also The acoustics of the chamber may be very

pg 5

PLATE 5

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

different when it is full from when it is empty empty seats reflect sound whereas an audience

absorbs sound

30 VIEW OF THE SEATING AND AUDIO VISUAL ARRANGEMENT IN THE

CHAMBER

pg 6

PLATE 6

stage areadirect sound

reverberated sound

Absorbed sound

seating area

Reverberated sound

PLATE 7 The interior view elevation

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

31 SOURCES OF INTERNAL AND EXTERNAL NOISE IN THE OLD SENATE

CHAMBER

In the process of analyzing the acoustics properties of the old senate chamber we analyze the

noise source both from the internal and external sources the noise from external areas ndashwhich is

commonly referred to as outdoor noise And noise from the internal spaces and from the

interactions- which are also referred to as indoor noise

These two categories would be considered in detail with the senate building as study

32 SOURCES OF OUTDOOR NOISE

1048707 VEHICULAR TRAFFIC Vehicles generate noise as they are driven in and out of the senate

area most especially close to the senate chamber itself at the lower floor Noise from the roads

opposite the chamber going to the auditorium possess several challenges most especially when a

program is been held at the auditorium the up and down movement of cars also increase the

noise in the environment But due to the low fenestration of the chamber it has a very

minimal effect on the interior as background noise

1048707 PEDESTRIAN AND CIRCULATION IN WALKWAYS since the senate building itself is

located in the busy bank area of the school pedestrian movement from different sources causes

much noise to the chamber This is also a disadvantage to the acoustic of the room most

especially because the senate chamber is located close to this pedestrian route Chatting shouting

and general sounds are part of the activities that produce the noise that is disseminated from the

pedestrian access roads also in the senate circulation area around the chamber pedestrian

pg 7

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

movement though restricted in a way still affects the acoustics of the room But again reduction

in the openings aids the room by reducing the noise from outside to its barest minimum

1048707 MECHANICAL NOISE FROM FUTA FM ELECTRICITY GENERATING PLANT

AND AC

The Futa FM generator is located near the old senate chamber and power outage during the day

causes the generator to be turned on hence noxious sounds are disseminated from this massive

plant due to ageing

Secondly the noises from the window unit AC around the chamber in the senate building also

add to the noise level

32 SOURCES OF INDOOR NOISE

bull Audience noise this is the noise that is usually disseminated from the audience in the room ie

the chamber users (students when invited for panel or other matters and lecturers both teaching

and non-teaching depending on the purpose of the use) this problem of audience is

fundamentally inevitable in acoustics as the users of the building must make sounds of different

sorts which could be as a result of talking coughing ringing of phones etc Though this effect is

at the minimum due to the materials used in the finishes of the room that absorb those sound

bull Mechanical noise

These are noise from the mechanical appliances in the room noise from the split unit ac and the

ceiling fans which is almost a constant source of noise in the room due to the fact that there is

pg 8

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

little or no natural ventilation in the room the only openings in the room are for lighting and not

ventilation which has both negative and positive impact on the room This are the two major

source of noise in the old senate chamber all other sources that could be found or associated

with the room has been taking care of with use of rugs wooden furniture foam

underlay wooden ceiling etc

40 ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE OLD SENATE

CHAMBER - EFFECTS OF THE INTERNAL AND EXTERNAL SOURCES OF NOISE

The acoustics characteristics of the space can be described under the following headings

The Background noise (external sources)

Reverberation and Echoes (Internal sources)

THE BACKGROUND NOISE

The Background noise that is transmitted into the interior spaces of the building has been

shielded and reduced to its barest minimum to a very good extent with the location of the

chamber in a less traffic area of the senate on the first floor the use of thick glass fixed windows

which has reduced the noise from the background leaving just the door as the only major

opening in the room All other sources of background noise like generators window unit ac

pedestrian movement etc affects majorly only when the doors are opened which is on a

minimal occasion

pg 9

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

REVERBERATION AND ECHOES

Reverberation is the persistence of sound in an enclosed space due to repeated reflection or

scattering after the sound source has stopped

Echo is a reflection of sound in a large room It is a distinct repetition of the original sound

though it is fainter because not all original sound is reflected

The design of the interiors space in the chamber is such that each person has a direct line of

auditory perception because of the way the room is constructed with stepped levels of seats

Although the walls surfaces are smooth and aids reflection the reverberation time is such that

speech is intelligent in the building

The materials used in the interior space are acoustics inclined For example the floor was ruged

and thick foam underlay layed under the rug which as a good sound absorbing ability the

ceiling materials for the sitting area are made of sound absorbing materials (wood) thus reducing

reflection However it is of note that echoes arenrsquot usually experienced in the room even though

the wall is of a smooth emulsion material

Note Reverberation is less when the room is put to use ie contains people because their bodies

absorb the sand waves and it also reduces the intensity of the sound but due to the cascading of

the seats it will not a be a problem because each person seated in row s will be able to hear well

without obstruction

pg 10

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

50 PROPOSAL FOR IMPROVING THE ACOUSTICS OF THE OLD SENATE

CHAMBER

This proposal is going to address this issue through two channels which would be methods of

reducing internal noise and methods of reducing external noise

51 REDUCTION OF INTERNAL NOISE

Basically the major acoustics materials that are meant to be put in place are already there ie the

floor material the ceiling etc but few things still needs to be checked and it listed as follows

1048707 Use of textured walls making the walls in the room a rough wall will help to diffuse the

sound coming from the speaker because the direct sound is disseminated around the room when

it impacts on these wall surfaces Hence a sensation of an ominous sound is heard A smooth

surface converges the sound to a point thereby distorting it Materials like cork particle board

felt wall carpets or wall papers help diminish internal noise in the space

1048707 Ceiling Finishes itrsquos important to cover the concrete part of the room with the use of the

suspended type of ceiling covering to create a void between the concrete slab and the space

below White perforated gypsum acoustic suspended ceiling boards could be used as a finish or

wood as used in other parts of the ceiling

1048707Installation of good AC unit with good silencer to replace the ceiling fans

The installation of more air-conditioning unit will eliminate the ceiling fan which reduces the

sound produced by the ceiling fan However these AC units should be sound proof to avoid

pg 11

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

generating noise and the already installed could be changed or serviced when necessary to

eliminate sound it might produce due to servicing

1048707full upholstery of seats Some seats have been replaced by a plastic chairs due to maybe

dilapidation of the former ones but they need to replace them back with full upholstery seats

52 REDUCTION OF EXTERNAL NOISE

Itrsquos deduced after considering the acoustics correction steps the major ways of rectifying the

external noise has already been put in place which is the insulation of the space the only thing

needed is that of the maintenance of the acoustics materials (thick glass n textured paints where

necessary) in case of damage and the use of textured wall like that of the interior

60 CONCLUSION

During the course of this research we can deduce that the treatment of the interior compartment

of any building most especially a room that is to be used as an auditorium is a very sensitive one

and should be monitored from start to finish ie from construction level to finish level Acoustics

studying of the senate chamber as helped in various ways and it will definitely have effects on

our careers both now and in the future Its successes and failure in buildings noise sources and

control and ways of apply it during design are well understood now to a better extent

pg 12

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13

70 REFERENCES

Prof Olu Ola Ogunsote Acoustics and noise control lecture notes

Diamant RME (1986) Thermal and acoustic insulation University Press Cambridge

httpwwwsdngnetcom

pg 13