UNIT KEJURUTERAAN ALAM SEKITAR UNIT KEJURUTERAAN ALAM SEKITAR JABATAN KEJURUTERAAN AWAM JABATAN KEJURUTERAAN AWAM

POLITEKNIK SULTAN IDRIS SHAH

CHAPTER 7CHAPTER 7EFFECT OF NOISE EFFECT OF NOISE

POLLUTIONPOLLUTION

2

Upon completion of this course, student should be able to :

Explain the effect of noise pollution to humans Justify Human Hearing Damage and Hearing Mechanism Relate noise pollution with interruption of human

communication Justify the effect of Human Health and Work Quality Explain Acoustics Privacy  Explain the effect of noise pollution to environment Determine the reduction of property loss Determine the effect on natural Environment Determine the effect on aesthetic values 

INTRODUCTION OF MECHANISM

Humans can generally hear sounds with frequencies between 20 Hz and 20 kHz.

Human hearing is able to discriminate small differences in loudness (intensity) and pitch (frequency) over that large range of audible sound.

Human hearing takes place by a complex mechanism involving the transformation of sound waves into nerve impulses

HUMAN HEARING MECHANISM Hearing is one of the five senses. The ear changes sound pressure waves

from the outside world into a signal of nerve impulses sent to the brain.

There are five section of the hearing mechanism work:

a) Outer ear c) Inner earb) Middle ear d) Acoustic

nervee) Central auditory system

Outer ear The visible portion of the outer ear in humans

is called the auricle or the pinna. It is a convoluted cup that arises from the opening of the ear canal on either side of the head.

The auricle helps direct sound to the ear canal. Both the auricle and the ear canal amplify and guide sound waves to the tympanic membrane or eardrum.

In humans, amplification of sound ranges from 5 to 20 dB for frequencies within the speech range (about 1.5–7 kHz). Since the shape and length of the human external ear preferentially amplifies sound in the speech frequencies, the external ear also improves signal to noise ratio for speech sounds.

TELINGA LUAR

Cuping- fungsi membantu

mengarahkan bunyi ke dalam lubang telinga dan akhirnya

menuju ke gegendang

telinga

Gegendang- berfungsi sebagai

sempadan dan hubungkan

telinga luar dan tengah

Lubang telingamerupakan hasil susunan tulang dan rawan yang dilapisi kulit tipis

Bentuk rumit telinga luar-fungsi untuk menangkap bunyiDalam saluran(lubang telinga) terdapat banyak kelenjar yang menghasilkan zat seperti lilin yang disebut serumen atau tahi telinga. Hanya bahagian saluran yang menghasilkan sedikit serumen yang memiliki rambut

Middle ear The eardrum is stretched across the front of a

bony air-filled cavity called the middle ear. Just as the tympanic membrane is like a drum head, the middle ear cavity is like a drum body.

Much of the middle ear's function in hearing has to do with processing sound waves in air surrounding the body into the vibrations of fluid within the cochlea of the inner ear. Sound waves move the tympanic membrane, which moves the ossicles, which move the fluid of the cochlea.

TELINGA TENGAHTulang tukul

(mealus) Tulang rakap(stapes) tulang terkecil di

tubuh

Tulang andas (indus)

tiub Eustachio -berfungsi agar tekanan udara di luar dan di dalam telinga seimbang

Bahagian telinga tengah ialah bahagian yang terkecil atau sempadannya yang tersempit antara bahagian-bahagian telinga.

FUNGSI: tulang-tulang tersebut memainkan peranan menghantar bunyi ke telinga dalam. 

Rongga telinga tengah, iaitu rongga yang berisi udara.

Inner ear The inner ear consists of the

cochlea and several non-auditory structures.

The cochlea has three fluid-filled sections, and supports a fluid wave driven by pressure across the basilar membrane separating two of the sections.

- Cochlear duct or scala media, contains an extracellular fluid similar in composition to

endolymph - Endolymph, which is

usually found inside of cells.

Diagrammatic longitudinal section of the cochlea

TELINGA DALAM

Salur bulat

Salur separuh bulat- fungsi sebagai Organ-organ

keseimbangan(tidak telibat dalam pendengaran)

Saraf auditori-bertugas menghantar implus yang diterima daripada koklea ke otak untuk ditafsirkan.

Jendela oval

Koklea –Berbentuk spiral dan berisi cairanberfungsi untuk menukarkan getaran yang diterima kepada impuls untuk dihantar ke otak melalui saraf auditoridikenali juga sebagai deria pendengaran sebenar. 

Organ terpenting

pendengaran

Central auditory system This sound information, now re-encoded,

travels down the auditory nerve, through parts of the brainstem (for example, the cochlear nucleus and inferior colliculus), further processed at each waypoint. The information eventually reaches the thalamus, and from there it is relayed to the cortex. In the human brain, the primary auditory cortex is located in the temporal lobe.

ACOUSTIC NERVE

Signal from these hair cells are translated into nerve impulses.

The nerve impulses are transmitted to the brain by the cochlear portion of the acoustic nerve (cranial nerve).

The acoustic nerve carries impulses from the cochlea to a relay station in the mid – brain, the cochlear nuclear.

PROSES PENDENGARANBunyi diterima

oleh cuping telinga

Bunyi dihantar ke salur auditori

Gegendang telinga bergetarkan

apabila menerima bunyi

Tulang-tulang osikal kuatkan

bunyi untuk dihantar ke koklea

Koklea menerima

bunyi

Sel-sel rerambut

koklea dirangsangkan

Impuls dihantar melalui saraf

auditori ke otak

Rangsangan ditafsirkan oleh otak

Noise has many effects on humans, including: Communication interference Sleep disruption Acoustic privacy Noise on performance Other effects

Noise pollution can have a considerable effect on communication. Many factors contribute to the effect of noise on communication interference, including : Similar frequency Higher ratio Culture factor Age of the people involved Situational factors

Noise interference with speech can lead to a large number of problems including: Hearing difficulties Lack of

concentration Fatigue Uncertainty Lack of self-

confidence Irritation Misunderstanding Decreased work

capacity

Human relation problems

Learning difficulties

Aggression Stress-related

reactions Behavioral

problems

Uninterrupted sleep is known to be a prerequisite for good physiologic and mental functioning in healthy individuals. Environmental noise is one of the major causes of disturbed sleep. When sleep disruption becomes chronic, the results are :

Mood changes Decrements in performance Long-term effects on health and well-being.

The primary sleep disturbance effects are:

Difficulty in falling asleep (increased sleep latency time)

Awakenings Alterations of sleep stages or depth,

especially a reduction in the proportion of REM-sleep

(REM = rapid eye movement)

Other primary physiological effects can also be induced by noise during sleep, including: Increased blood pressure Increased heart rate Increased pulse amplitude Vasoconstriction Changes in respiration Cardiac arrhythmias Increased body movement

Sleep disturbance by noise is affected by:

Characteristics of the noiseType of stimulus The stage of sleep Individual variables

ACOUSTICS PRIVACY

Acoustics privacy effect of the change to an individual due to changes in the sound at a time. These symptoms occur due to changes in sound level that occurs suddenly. Acoustics privacy effects can be felt by the individual concerned

THE EFFECTS OF ACOUSTICS PRIVACY• Mental changes, the individual will be under pressure, loss of concentration (not known by others).• Changes in attitude that is depressed,  irritable and rampage.• Changes in performance is the quality of work quality is affected.

EXAMPLE OF ACOUSTICS PRIVACY Ordinary people working in

the office will have a acoustics privacy when working in noisy factory environment.

Students are studying will have acoustics privacy music when installing  roommate who is very strong.

Acoustic comfort for everyone

EFFECT NOISE POLLUTION TO ENVIRONEMNT

Noise is really any unwanted sound, some sound that isn't natural to given environment and it causes disturbance to not only natural processes but can also cause harm to human society.

Noise pollution can become big environmental problem in some areas.

It is not only stressful to many animals but can also cause the problems in predator/prey relation and detection, and even lead to different reproduction problems.

Exposure too much noise can lead to stress, aggression, sleep disturbance, hearing loss, and different other psychological issues.

The most common source of noise pollution is transportation, in form of motor vehicles.

Some other sources like car alarms, emergency service sirens, office equipment, factory machinery, and construction work, barking dogs, power tools, lighting hum, different audio systems, loudspeakers and noisy people can also cause noise pollution but motor vehicles are globally speaking dominant source of noise pollution.

1) Hearing Impairment

Hearing impairment is typically defined as an increase in the threshold of hearing as clinically assessed by audiometry. Impaired hearing may come from the workplace, from the community, and from a variety of other causes (eg, trauma, ototoxic drugs, infection, and heredity).

Noise induced hearing impairment may be accompanied by abnormal loudness perception (loudness recruitment), distortion (paracusis), and tinnitus.

2) Sleep Disturbances

Environmental noise is one of the major causes of disturbed sleep. When sleep disruption becomes chronic, the results are mood changes, decrements in performance, and other long-term effects on health and well-being.

Much recent research has focused on noise from aircraft, roadways, and trains. It is known, for example, that continuous noise in excess of 30 dB disturbs sleep.

The primary sleep disturbances are difficulty falling asleep, frequent awakenings, waking too early, and alterations in sleep stages and depth, especially a reduction in REM sleep.

Secondary effects (so-called after effects) measured the following day include fatigue, depressed mood and well-being, and decreased performance.

Decreased alertness leading to accidents, injuries, and death has also been attributed to lack of sleep and disrupted circadian rhythms.

Long-term psychosocial effects have been related to nocturnal noise. Noise annoyance during the night increases total noise annoyance for the following 24 hours. Particularly sensitive groups include the elderly, shift workers, persons vulnerable to physical or mental disorders, and those with sleep disorders.

3) Cardiovascular Disturbances

A growing body of evidence confirms that noise pollution has both temporary and permanent effects on humans (and other mammals) by way of the endocrine and autonomic nervous systems.

It has been postulated that noise acts as a nonspecific biologic stressor eliciting reactions that prepare the body for a fight or flight response.

For this reason, noise can trigger both endocrine and autonomic nervous system responses that affect the cardiovascular system and thus may be a risk factor for cardiovascular disease. These effects begin to be seen with long-term daily exposure to noise levels above 65 dB or with acute exposure to noise levels above 80 to 85 dB.

DETERMINE THE REDUCTION OF PROPERTY LOSS

The effect of noise on property values can drop in property values located near the source. Linked to a fall in property values usually are caused by the noise of vehicles, but this effect is related only to the value of a home. However, the impact on the reduction in property value may be more influenced by their own humanity.

For example, the placement of property in a location that is considered special as close to center city or an area with public facilities may be able to overcome the loss due to noise. Therefore, its value will not decrease even if there is noise due to the higher priority given to the factor of public facilities.

The factor :

Noise Traffic - noise caused by transport can be divided into three main sources is

traffic, aircraft and train.- Factor that influence of traffic noise :

a) Structure of road and types of road :- The road made from concrete will effect 5dBA noise pollution.- Wet road will also make a noise pollution more than a dry road.

b) Speed of vehicles :- The more the speed of a vehicle, the more noise will the vehicle made.

c) The ratio of trucks routes:- If there are more trucks through the road, the noises will increase.- Because trucks is the most noisy vehicles on the roads.

d) Factor of weather :- The factor of weather depends on the temperature and wind. - Overseas studies shows that, the temperature can make a changes

for a noise pollution about 20 dBA (maximum), while wind can changes about 30 dBA.

e) Reflection from buildings :- Noises from the road, can reflect to the wall from buildings that are

constructed near from the road.

Aeroplanes - Noise from aeroplane is the most significant for community live

near the airport.- Noise of aeroplane depends on the types of aeroplanes, engine and

the maintenance of the aeroplane. Train - The problem of this types noise pollution is the most significant

for community who lives in rural areas that are usually had a railways near from their house.

- The noise is made up from the wheels and the railways.- The noise is also made from the wissel of the train.- The noise also changes depends on the types, and structure of

railways.

Determine the effect on natural environment

Noise pollution on marine life

Ship engine, seismic air guns , and advanced military sonars are making the world’s seas and ocean so noisy that they threaten the lives of marine animals that rely on sound, wildlife.

Ship engines, seismic air guns, and advanced military sonars are making the world's seas and oceans so noisy that they threaten the lives of marine animals that rely on sound.

One growing concern is the use of seismic air guns, devices towed behind a ship that produce an acoustic pulse, used to detect oil and gas reserves beneath the seabed

Effect of noise pollution on air

A flying airplane produces harsh reverberating sounds with the use of several air pollutants that can directly affect the Earth’s climate system. As these airplanes emit nerve wracking sounds the aircraft likewise emits pollutants from its engine exhausts.

Effect of noise pollution on Land and on Sea

On Land

Automobiles, trains, and farm tractors immediately affect our physical well-being, not only by the intrusive sounds that can cause hearing impairment and hypertensions.

The intensity of the noise pollution we hear connotes that these vehicles and equipment are in motion and therefore pumping more carbon dioxide emissions in the atmosphere, at the highest level.

as autos, smaller trucks, buses and motorcycles wait it out in the heavy traffic, these vehicles continuously emit both noise, and air pollutants as motors and exhaust systems are kept running.

On the sea Other studies concerning boat noises, seismic testing,

and other offshore developments provide leads that they are also possible causes in the disruption of marine ecology.

noise pollution remediable by soundproofing materials, noise barriers, and white noise machines or simply moving out of the city carries a far greater significance in terms of environmental pollution

The effect noise pollution on aesthetic value

Noise Pollution can be decrease aesthetic value of property which is located close with their causes.

Main cause a fall in property values usually are caused by the noise of vehicles, but this effect is related only to the value of a home, while the property for industrial or commercial, the reverse may occur because of factors accessibility.

EFFECT NOISE POLLUTION ON AESTHETIC VALUE

1.In Los Angeles. Properties (land) that are exposed to jet noise at Los Angeles International Airport have been diminished in value between 10-20% (McValue, in Bragdon, 1975).

2.In the United States has proposed that the decline in house prices of 0.4% for each increase in noise level of 1 dBA if the property (land) is exposed to traffic noise (Pearce and Friends, 1984).

3. In Canada, residential zone are located near the rail, the price home will declined as compared to 500 to 1000 feet from the runway.

4.In Sacramento, California home that adjacent to the highway would take 10 months to sell compared to houses are located far from the highway.

THE EFFECT NOISE POLLUTION ON AESTHETIC VALUE

HOWEVER, the impact on the reduction of land value of property may be more influenced by the human factor itself.

EXAMPLE

The placement of property in a location that is considered special as close to centre city or an area with public facilities may be able to overcome the loss due to noise. Therefore, its value will not decrease even if there is noise due to the higher priority given to the factor of public facilities.

Studies in New York showed that home buyers facing the main road or highway Long Island is willing to pay a higher price for the house despite having to face the problem of noise. This selection is made for the area allows travel faster and can avoid traffic congestion. (James 1977).