A WRITE UP ON

JULY, 2014

PROCEDURES FOR ACOUSTIC ANALYSIS OF EXISTING PROJECT SITES

COMPILED BY: ARC/09/ 7338 ABIOLA NURUDEEN E.K ARC/09/7340 ADARAMOLA OLUWASEUN I.

SUBMITTED IN PARTIAL FUFILMENT OF THE REQUIREMENT FOR THE AWARD OF BACHELOR OF TECHNOLOGY IN ARCHITECTURE

TO

THE DEPARTMENT OF ARCHITECTURESCHOOL OF ENVIRONMENTAL TECHNOLOGY

F E D E R A L U N I V E R S I T Y O F T E C H N O L O G Y

TABLE OF CONTENTS pages

ABSRACT 3

1.0 INTRODUCTION 4-5

2.0 PROCEDURES FOR ACOUSTIC ANALYSIS OF EXISTING PROJECT SITE 6

2.1 REVIEW THE PROJECT DOCUMENTATION 6

2.2 PERFORM ACOUSTICAL ANALYSIS 6

2.2.1 STATIONARY NOISE MODELING 6

2.2.2 NOISE MEASUREMENT 7

2.2.3 PROCEDURES FOR NOISE MEASUREMENT 7-8

Plate 1…………………………………………………………………………….8

Plate 2…………………………………………………………………………….9

3.0 CONCLUSION 10

4.0 RECOMMENDATIONS 11

6.0 REFERENCES 12

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ABSTRACT

Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in

gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who

works in the field of acoustics is an acoustician while someone working in the field of acoustics

technology may be called an acoustical engineer. The application of acoustics is present in

almost all aspects of modern society with the most obvious being the audio and noise control

industries.

Acoustic analysis which is also known as acoustic phonetics is a subfield of phonetics which

deals with acoustic aspects of speech and noise. This came to life with the need for students to

understand the planning of spaces both interior and exterior, as well as to be able to design

acoustically functional spaces that will enhance the intelligibility of sound or speech.

In addition to this, there is a rapid increase in loss of hearing caused by agents of hearing

damage such as threshold shifts, sociocusis, due to an uncontrolled means of sound propagation.

Hence, the need for the study of acoustics and infact the materials used to enhance it.

Learning the procedures for acoustic analysis of an existing site gives you the advantage of how

to apply material when building is going on and after the project is completed.

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1.0 INTRODUCTION

What is acoustics?

Acoustics is the interdisciplinary science that deals with the study of all mechanical

waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound.

A scientist who works in the field of acoustics is an acoustician while someone working

in the field of acoustics technology may be called an acoustical engineer. The application

of acoustics is present in almost all aspects of modern society with the most obvious

being the audio and noise control industries.

Acoustics is the science of sound in general. It is more commonly used for the special

branch of that science, architectural acoustics deals with the construction of enclosed

areas so as to enhance the hearing of speech or music. It could as well be regarded as the

branch of architecture that deals with the control of sound which showcases the

reflective, absorptive properties of sound. Acoustics is a subject that describes all aspects

of sound and falls into the fields of both science and art. The science of sound envelops

the technicalities of its generation, propagation and reception as well as objectively

describing its qualities. In the artistic world, sound plays a large part in terms of the

spoken word, music and other auditory experiences that give us pleasure. In most cases,

the acoustics of a room will be satisfactory if a proper balance between sound-absorbing

and sound-reflecting materials is created. In achieving this, reverberation as a factor

should be taken into consideration. For modifying the reverberations, the architect has

two types of materials, sound- absorbent and sound-reflecting, to coat the surfaces of

ceilings, walls, and floors. Soft materials such as cork and felt absorb most of the sound

that strikes them, although they may reflect some of the low-frequency sounds. Hard

materials such as stone and metals reflect most of the sound that strikes them. The

acoustics of a large auditorium may be very different when it is full from when it is

empty; empty seats reflect sound, whereas an audience absorbs sound. Hence, a study of

the acoustic properties of various building materials in order to broaden the scope of the

students of architecture and to facilitate the selection of quality materials that will ensure

good acoustics all round a space is needed. It should however be noted that there are

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various materials used to achieve a good acoustic in construction, but for the purpose of

this analysis, few number of materials will be mentioned.

Acoustic analysis evaluates the potential noise impacts and necessary mitigation

measures for a particular existing project site.

This paper clearly evaluates the procedures involved for acoustic analysis of an existing

project site.

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2.0 PROCEDURES FOR ACOUSTIC ANALYSIS OF EXISTING PROJECT SITE

2.1 REVIEW THE PROJECT DOCUMENTATION (OWNERS

REQUIREMENTS, DRAWINGS, SPECIFICATION etc)

This is the very first step to take when making acoustic analysis of an existing project

site. It has to do with identifying the site, noting the sources of noise, perusing the

drawings, specifications and materials of buildings on the project site

2.2 PERFORM ACOUSTICAL ANALYSIS

Typically, a “one-hour” equivalent sound level measurement (LEQ, A-Weighted) is

recorded for at least one noise-sensitive location on the site. If sufficient traffic is

present during the on-site noise measurement, start and end times are recorded and

vehicle counts are made for cars, medium trucks, and heavy trucks for the

corresponding road segment(s). Supplemental sound measurements of one hour or

less in duration are often made to further describe the noise environment of the site.

For measurements of less than one hour in duration, the measurement time must be

long enough for a representative traffic volume to occur and the noise level (LEQ) to

stabilize; 15 minutes is usually sufficient for this purpose. The vehicle counts are

then converted to one-hour equivalent volumes. Other field data gathered include

measuring or estimating distances, angles-of-view, slopes, elevations, roadway

grades, and vehicle speeds. These data were checked against available maps and

records.

2.2.1 STATIONARY NOISE MODELING

This Stationary Noise analysis uses a version of Acoustic Regulations model, together

with several key site parameters to project the expected impacts on the existing land

uses (project site) as a result of the proposed development.

Simliar performance equations including relative source-barrier-receiver horizontal

separations, relative source-barrier-receiver vertical separation, typical noise source

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spectra and barrier transmission loss from the stationary noise model were utilized to

complete the stationary source model.

Horizontal Geometry

Stationary noise source distance based upon building locations and adjacent land

sensitive use receivers.

Vertical Geometry

Height above pad grade for each stationary source. These assumptions and the site

plan are used to fix the horizontal and vertical geometry used in the barrier analysis

2.2.2 NOISE MEASUREMENT

Noise measurements are taken to determine the existing noise levels. A noise receiver

or receptor might produce an impact. The following criteria are used to select

measurement locations and receptors.

Locations expected to receive the highest noise impacts, such as first row (floor)

of houses.

Locations that are acoustically representative and equivalents of the area concern.

Human land usage

2.2.3 PROCEDURES FOR NOISE MEASUREMENT

Microphones for sound level meters are placed above ground for all

measurements.

Sound Level Meter (SLM) must be calibrated before and after each measurement.

Following the calibration of equipment, a wind screen must be placed over the

microphone.

Frequency weighting is set as “A” and slow response.

Results on the short-term noise measurements will be recorded on the field data

sheets.

During short-term noise measurements, any noise contaminations such as local

traffic, barking dogs, lawn mowers or aircraft flyovers must be recorded.

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Temperature and sky conditions are to be observed and documented.

Plate 1: Sound Level Meter (SLM)

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Plate 2: Sound Level Meter (SLM)

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3.0 CONCLUSION

Having followed all the procedures for acoustic analysis of an existing project site. The

project will be assessed with respect to on-site and off-site generated noise. The projected

stationary noise analysis will indicate that noise levels associated with the project and will

be below the City’s Acoustic regulations.

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4.0 RECOMMENDATIONS

Acoustic considerations in buildings cannot be over-emphasized. Therefore design team members have to be advised and sensitized on what acoustical criteria should be achieved and how to achieve it in their subsequent designs.

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5.0 REFERENCES

Acoustical Surfaces, Inc. What is acoustics?, retrieved 2010-07-29 Acoustical Society of America. "Acoustics and You (A Career in Acoustics?)". National Council of Acoustical Consultants

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