MOUNT ZION COLLEGE OF ENGINEERING AND TECHNOLOGY

MOUNT ZION COLLEGE OF ENGINEERING AND TECHNOLOGY
DEPARTMENT OF CIVIL ENGINEERING UNIT 5 - NOISE POLLUTION 5.1. Sources of noise pollution 5.2. Effects 5.3. Assessment 5.4. Standards 5.5. Control methods 5.6. Prevention MZCET/CIVIL/IV/CE6011/APM/5 CE AIR POLLUTION MANAGEMENT

MZCET/CIVIL/IV/CE6011/APM/5
Sound Sound is a vibration that propagates as a mechanical wave of pressure and displacement, through some medium (i.e. air or water). Sound refers to only those vibrations with frequencies that are within the range of hearing for human. MZCET/CIVIL/IV/CE6011/APM/5

Noise Noise is basically any unwanted sound. It is measured in dB units. Sound Noise MZCET/CIVIL/IV/CE6011/APM/5

Characteristics of Noise
Sound pressure Frequency Duration Time of the day Location Intermittency MZCET/CIVIL/IV/CE6011/APM/5

Kinds of Noise Continuous Variable or Intermittent Impulse or Impact Kinds of noise which affect analysis Chemical Noise Instrumental Noise MZCET/CIVIL/IV/CE6011/APM/5

Variable Noise Impulse Noise Continuous Noise MZCET/CIVIL/IV/CE6011/APM/5

Instrumental Noise Thermal Noise Flicker Noise Shot Noise Environmental Noise MZCET/CIVIL/IV/CE6011/APM/5

WHAT IS NOISE POLLUTION?
Sound that is unwanted or disrupts one’s quality of life is called as noise. When there is lot of noise in the environment, it is termed as noise pollution. Sound becomes undesirable when it disturbs the normal activities such as working, sleeping, and during conversations. It is an underrated environmental problem because of the fact that we can’t see, smell, or taste it. World Health Organization stated that “Noise must be recognized as a major threat to human well-being” MZCET/CIVIL/IV/CE6011/APM/5

5.1 Sources of Noise Pollution
Household Sources Social Events Commercial and Industrial Activities Transportation MZCET/CIVIL/IV/CE6011/APM/5

Sources of Noise Pollution
Transportation systems are the main source of noise pollution in urban areas. Construction of buildings, highways, and streets cause a lot of noise, due to the usage of air compressors, bulldozers, loaders, dump trucks, and pavement breakers. Industrial noise also adds to the already unfavorable state of noise pollution. Loud speakers, plumbing, boilers, generators, air conditioners, fans, and vacuum cleaners add to the existing noise pollution. MZCET/CIVIL/IV/CE6011/APM/5

Household Sources Food Mixer Grinder Vacuum Cleaner
5.1 Sources of Noise Pollution contd… Food Mixer Grinder Vacuum Cleaner Washing machine and Dryer Air Conditioner Straighter and curlers Cooler TV iPods and Earphones Loud speaker Neighbor's Barking Dog MZCET/CIVIL/IV/CE6011/APM/5

5.1 Sources of Noise Pollution contd…
MZCET/CIVIL/IV/CE6011/APM/5

Social Events Places of Worship Discos and Gigs Parties
5.1 Sources of Noise Pollution contd… Places of Worship Discos and Gigs Parties Markets where people sell goods with loudspeaker. When these events are not often, they can be termed as nuisance rather than noise pollution. MZCET/CIVIL/IV/CE6011/APM/5

Commercial and Industrial Activities
5.1 Sources of Noise Pollution contd… Printing Presses Manufacturing Industries Construction Sites MZCET/CIVIL/IV/CE6011/APM/5

Sources of Construction Noise
5.1 Sources of Noise Pollution contd… Pneumatic Hammers Air Compressors Bulldozers Loaders Dump Trucks Pavement breakers MZCET/CIVIL/IV/CE6011/APM/5

Sources of Industry Noise
5.1 Sources of Noise Pollution contd… Fans Motors Compressors mounted outside This interior noise sources have significant impacts on industrial workers, among whom noise induced hearing loss is unfortunately common MZCET/CIVIL/IV/CE6011/APM/5

Transportation Road Traffic Noise Aircraft Noise Noise from Rail Roads
5.1 Sources of Noise Pollution contd… Transportation Road Traffic Noise Aircraft Noise Noise from Rail Roads MZCET/CIVIL/IV/CE6011/APM/5

Causes of Noise Pollution
5.1 Sources of Noise Pollution contd… Poor Urban Planning Sounds from Motor Vehicles Sounds from Musical Instruments Car Alarms Office Equipment Factory Machinery MZCET/CIVIL/IV/CE6011/APM/5

Causes of Noise Pollution
5.1 Sources of Noise Pollution contd… Construction Work Barking Animals Appliances Audio Instruments Loud Speakers Noise Created by People MZCET/CIVIL/IV/CE6011/APM/5

Solutions for Noise Pollution
Planting bushes and trees in and around sound generating sources is an effective solution for noise pollution. Regular servicing and tuning of automobiles can effectively reduce the noise pollution. Buildings can be designed with suitable noise absorbing material for the walls, windows, and ceilings. Workers should be provided with equipments such as ear plugs and earmuffs for hearing protection. MZCET/CIVIL/IV/CE6011/APM/5

Similar to automobiles, lubrication of the machinery and servicing should be done to minimize noise generation. Soundproof doors and windows can be installed to block unwanted noise from outside. Regulations should be imposed to restrict the usage of play loudspeakers in crowded areas and public places. Factories and industries should be located far from the residential areas. MZCET/CIVIL/IV/CE6011/APM/5

Community development or urban management should be done with long-term planning, along with an aim to reduce noise pollution. Social awareness programs should be taken up to educate the public about the causes and effects of noise pollution. MZCET/CIVIL/IV/CE6011/APM/5

5.2. Effects of Noise Pollution
Effects on Human Effects on Animals Effects on Environment (Vegetation, Property) MZCET/CIVIL/IV/CE6011/APM/5

Health Effects According to the USEPA, there are direct links between noise and health. Also, noise pollution adversely affects the lives of millions of people. Noise pollution can damage physiological and psychological health. High blood pressure, stress related illness, sleep disruption, hearing loss, and productivity loss are the problems related to noise pollution. It can also cause memory loss, severe depression, and panic attacks. MZCET/CIVIL/IV/CE6011/APM/5

5.2. Effects of Noise Pollution contd…

Effects on Human Hearing Impairment
5.2. Effects of Noise Pollution contd… Hearing Impairment Interference with Spoken Communication Decrease in Efficiency Lack of Concentration Fatigue Sleep Disturbances Cardiovascular Disturbances MZCET/CIVIL/IV/CE6011/APM/5

Disturbance in Mental Health Impaired Task Performance
5.2. Effects of Noise Pollution contd… Disturbance in Mental Health Impaired Task Performance Negative Social Behavior and Annoyance reactions Abortion Abnormal Fetus Temporary or Permanent Deafness MZCET/CIVIL/IV/CE6011/APM/5

Diseases Caused by Noise Pollution
5.2. Effects of Noise Pollution contd… High Blood Pressure Heart Attack Cancer Asthma Coughing, wheezing Deafness Annoyance Stress Anxiety Reduced lung development Bronchitis Insomnia Arterious Clerosis MZCET/CIVIL/IV/CE6011/APM/5

Effect on Animals Damages Nervous system
5.2. Effects of Noise Pollution contd… Effect on Animals Damages Nervous system Altering Prey/predator detection Creates problems in Navigation They become Dangerous and Attacking Raise Metabolism Reduction of useable Habitat Death of Certain Species Genetic and Evolutionary Problems MZCET/CIVIL/IV/CE6011/APM/5

Continued….. Hormone imbalance Chronic Stress
5.2. Effects of Noise Pollution contd… Continued….. Hormone imbalance Chronic Stress Panic and Escape Behavior Abandonment of Offspring Injury Loudness of Interspecies Communication MZCET/CIVIL/IV/CE6011/APM/5

Effects on Environment
5.2. Effects of Noise Pollution contd… Effects on Environment Breakage of Earth Barrier Poor Quality of Crops Damages Buildings, bridges and Monuments Weakens the Edifice of Building MZCET/CIVIL/IV/CE6011/APM/5

Control of Noise Pollution
5.2. Effects of Noise Pollution contd… Control of Noise Pollution Control at Source Control in the Transmission Path Using Protective Equipment MZCET/CIVIL/IV/CE6011/APM/5

Control at Source Reducing the Noise Levels from Domestic Sectors
5.2. Effects of Noise Pollution contd… Control at Source Reducing the Noise Levels from Domestic Sectors Maintenance of Automobiles Use of Economic instruments Control over Vibrations Low Voice Speaking Prohibition on Usage of loudspeakers Selection of Machinery Maintenance of Machines MZCET/CIVIL/IV/CE6011/APM/5

Control in the Transmission Path
5.2. Effects of Noise Pollution contd… Control in the Transmission Path Installation of Barriers Installation of Panels and Enclosures Green Belt development MZCET/CIVIL/IV/CE6011/APM/5

Using Protection Equipment
5.2. Effects of Noise Pollution contd… Job Rotation Exposure Reduction Hearing Protection Protection at the Receiver End MZCET/CIVIL/IV/CE6011/APM/5

More Noise Control Techniques
5.2. Effects of Noise Pollution contd… Sound insulation Sound Absorption Vibration Damping Vibration Isolation Urban Planning Public Education and Awareness MZCET/CIVIL/IV/CE6011/APM/5

5.3. Noise assessment A noise assessment is an examination of the nature and characteristics of a noise. It may involve verifying aural factors such as: The location of the noise source Its audibility at certain locations The time the noise is made and its duration Its characteristics The reported effect it has on people. MZCET/CIVIL/IV/CE6011/APM/5

5.3. Noise assessment contd…
Definition of offensive noise: Depending on the type of noise under consideration, noise can be considered as offensive in three ways according to its: Audibility Duration Inherently offensive characteristics. MZCET/CIVIL/IV/CE6011/APM/5

Duration of noise test for intruder alarms: It does not matter whether the alarm sounds continuously or intermittently. For example, a car alarm that sounds for 30 seconds, stops for 1 minute and then sounds again for another 30 seconds is taken to sound for 60 seconds, which is more than the 45 seconds prescribed for a vehicle alarm manufactured on or after 1 September 1997. For building intruder alarms, the assessment needs to be made inside a habitable room in a neighbour’s residence. For vehicle intruder alarms the assessment can be made anywhere. MZCET/CIVIL/IV/CE6011/APM/5

The times of use or duration of the noise automatically make the noise offensive. In other cases it will be necessary to consider a range of factors to determine whether the noise is offensive, including the following: The loudness of the noise, especially compared with other noise in the area The character of the noise The time and duration of the noise Whether the noise is typical for the area How often the noise occurs The number of people affected by the noise. MZCET/CIVIL/IV/CE6011/APM/5

Assessing noise with a sound level meter:
5.3. Noise assessment contd… Assessing noise with a sound level meter: A sound level meter should be used to measure noise levels when: Determining an acceptable noise level for inclusion in a planning approval or a Noise Control Notice or Prevention Notice Testing whether a particular noise complies with a level prescribed in a planning approval or notice MZCET/CIVIL/IV/CE6011/APM/5

Gathering evidence to support an offensive noise test, such as:
5.3. Noise assessment contd… Gathering evidence to support an offensive noise test, such as: – quantifying how loud the noise is – assessing how loud it is relative to the background noise (see subsection ‘Intrusive noise’, below) – determining the presence of annoying characteristics such as tones supporting a prosecution or disputed Penalty Notice. MZCET/CIVIL/IV/CE6011/APM/5

Intrusive noise Noise is identified as ‘intrusive’ if it is noticeably louder than the background noise and considered likely to disturb or interfere with those who can hear it. MZCET/CIVIL/IV/CE6011/APM/5

Measuring noise Noise measurements should be undertaken by officers properly trained to use noise equipment. If you are inexperienced with noise measurements, it is desirable that you get to know what typical decibel levels sound like. Become familiar with the sound level meter and its controls. MZCET/CIVIL/IV/CE6011/APM/5

Decide when the noise is representative of the worst case level of noise from the source or activity being investigated and take measurements at this time. Avoid taking measurements when it is raining or the average wind speed exceeds 5 metres per second at microphone height. Calibrate the sound level meter before and after each set of noise measurements MZCET/CIVIL/IV/CE6011/APM/5

Ensure the sound level meter is in the correct position. Measure the noise under investigation for long enough to establish that the measured value is representative of the subject noise. Measure the noise at the location where the impact occurs. When the noise under investigation is affected by extraneous noise, be sure that the subject noise is what you are measuring. MZCET/CIVIL/IV/CE6011/APM/5

Sequence of steps for measuring noise
5.3. Noise assessment contd… Sequence of steps for measuring noise Before going out to take a measurement, check that the sound level meter has a current calibration certificate issued by an accredited laboratory (for example, NATA). Familiarize yourself with the meter and its settings. Select a representative location and time of day to take measurements, taking into account information about the subject noise and any complaints received. MZCET/CIVIL/IV/CE6011/APM/5

Do a field calibration of the sound level meter
5.3. Noise assessment contd… Set the microphone at 1.2 to 1.5 metres above the ground and, where feasible, avoid measurements within 3 metres of any walls, buildings and other reflecting surfaces. Ensure weather conditions are suitable: no rain and a wind speed of less than 5 m/s and note these prevailing conditions in a log book. Do a field calibration of the sound level meter MZCET/CIVIL/IV/CE6011/APM/5

Measure the subject noise for a pre-determined period (such as 15 minutes) and check that the selected descriptor (for example LAeq) is suitable. If there is variation in the source noise level during the set period of measurement, increase your confidence in the value being representative of the worst case by taking a second and perhaps a third reading for the same period of time. If necessary, measure the LA90 background noise level for the same set period in the absence of the subject noise. MZCET/CIVIL/IV/CE6011/APM/5

Where noise other than that under consideration occurs during measurement, take another reading to avoid the readings being contaminated. At the end of the measurements do another field calibration of the sound level meter. If there is more than a 1 decibel variation between the calibrated level and the first calibrated level, the measurements may be invalid, in which case the measurement procedure will need to be repeated. MZCET/CIVIL/IV/CE6011/APM/5

Document observations of weather and noise that were heard during the measurements, including the time of specific events that may affect readings, such as a frog croaking or a dog barking. MZCET/CIVIL/IV/CE6011/APM/5

Noise rating Equivalent sound level, Leq : It is the constant sound pressure level which would have produced the same total energy as the actual sound level over the given time. It is denoted as Leq. Leq = equivalent continuous sound pressure level in dB p0 = reference pressure level (typically 20 µPa) pA = acquired sound pressure t1 = start time for measurement t2 = end time for measurement MZCET/CIVIL/IV/CE6011/APM/5

Noise rating L10, L50 and L90 : L10 is the level exceeded for 10% of the time. For 10% of the time, the sound or noise has a sound pressure level above L10. For the rest of the time, the sound or noise has a sound pressure level at or below L10. These higher sound pressure levels are probably due to sporadic or intermittent events. L50 is the level exceeded for 50% of the time. It is statistically the mid-point of the noise readings. It represents the median of the fluctuating noise levels. MZCET/CIVIL/IV/CE6011/APM/5

Noise rating L90 is the level exceeded for 90% of the time. For 90% of the time, the noise level is above this level. It is generally considered to be representing the background or ambient level of a noise environment. MZCET/CIVIL/IV/CE6011/APM/5

Noise rating Perceived Noise Levels (PNL) The noise of aircraft is described in terms of Perceived Noise Levels (PNL), a scale of noisiness, expressed in pNdB. Ldn The day-night equivalent value of sound level. The day is counted from 6AM to 9PM (15hrs) and night from 9PM- 6AM (9hrs). MZCET/CIVIL/IV/CE6011/APM/5

5.4. Standards of noise pollution
Whereas the increasing ambient noise levels in public places from various sources, inter-alia, industrial activity, construction activity, fire crackers, sound producing instruments, generator sets, loud speakers, public address systems, music systems, vehicular horns and other mechanical devices have deleterious effects on human health and the psychological well being of the people; MZCET/CIVIL/IV/CE6011/APM/5

5.4. Standards of noise pollution contd…
it is considered necessary to regulate and control noise producing and generating sources with the objective of maintaining the ambient air quality standards in respect of noise Whereas a draft of Noise Pollution (Control and Regulation) Rules, 1999 was published under the notification of the Government of India in the Ministry of Environment and Forests vide number S.O. 528 (E), dated the 28th June, 1999 MZCET/CIVIL/IV/CE6011/APM/5

Ambient air quality standards in respect of noise for different areas/zones.- The State Government shall categorize the areas into industrial, commercial, residential or silence areas / zones for the purpose of implementation of noise standards for different areas. An area comprising not less than 100 meters around hospitals, educational institutions and courts may be declared as silence area / zone for the purpose of these rules. MZCET/CIVIL/IV/CE6011/APM/5

The State Government shall take measures for abatement of noise including noise emanating from vehicular movements, blowing of horns, bursting of sound emitting firecrackers, use of loud speakers or public address system and sound producing instruments and ensure that the existing noise levels do not exceed the ambient air quality standards specified under these rules. MZCET/CIVIL/IV/CE6011/APM/5

Day time shall mean from 6.00 a.m. to p.m. Night time shall mean from p.m. to 6.00 a.m. MZCET/CIVIL/IV/CE6011/APM/5

* dB(A) Leq denotes the time weighted average of the level of sound in decibels on scale A which is relatable to human hearing. A “decibel” is a unit in which noise is measured. “A”, in dB(A) Leq, denotes the frequency weighting in the measurement of noise and corresponds to frequency response characteristics of the human ear. Leq: It is an energy mean of the noise level over a specified period. MZCET/CIVIL/IV/CE6011/APM/5

2. Responsibility as to enforcement of noise pollution control measures.- The noise levels in any area / zone shall not exceed the ambient air quality standards in respect of noise as specified in the Schedule. The authority shall be responsible for the enforcement of noise pollution control measures and the due compliance of the ambient air quality standards in respect of noise. MZCET/CIVIL/IV/CE6011/APM/5

3. Restrictions on the use of loud speakers / public address system and sound producing instruments: A loud speaker or a public address system shall not be used except after obtaining written permission from the authority. A loud speaker or a public address system or any sound producing instrument or a musical instrument or a sound amplifier shall not be used at night time except in closed premises for communication within, like auditoria, conference rooms, community halls, banquet halls or during a public emergency. MZCET/CIVIL/IV/CE6011/APM/5

The noise level at the boundary of the public place, where loudspeaker or public address system or any other noise source is being used shall not exceed 10 dB (A) above the ambient noise standards for the area or 75 dB (A) whichever is lower; The peripheral noise level of a privately owned sound system or a sound producing instrument shall not, at the boundary of the private place, exceed by more than 5 dB (A) the ambient noise standards specified for the area in which it is used. MZCET/CIVIL/IV/CE6011/APM/5

4. Restrictions on the use of horns, sound emitting construction equipments and bursting of fire crackers:- No horn shall be used in silence zones or during night time in residential areas except during a public emergency. Sound emitting fire crackers shall not be burst in silence zone or during night time. Sound emitting construction equipments shall not be used or operated during night time in residential areas and silence zones. MZCET/CIVIL/IV/CE6011/APM/5

5. Consequences of any violation in silence zone / area. Whoever, in any place covered under the silence zone / area commits any of the following offence, he shall be liable for penalty under the provisions of the Act:- whoever, plays any music or uses any sound amplifiers, whoever, beats a drum or tom-tom or blows a horn either musical or pressure, or trumpet or beats or sounds any instrument, or whoever, exhibits any mimetic, musical or other performances of a nature to attract crowds. whoever, bursts sound emitting fire crackers; or whoever, uses a loud speaker or a public address system. MZCET/CIVIL/IV/CE6011/APM/5

6. Noise limits for vehicles at manufacturing stage

5.5. Control of Noise Pollution
Noise generation is associated with most of our daily activities. A healthy human ear responds to a very wide range of SPL from - the threshold of hearing at zero dB, uncomfortable at dB and painful at dB(3). Due to the various adverse impacts of noise on humans and environment, noise should be controlled. The technique or the combination of techniques to be employed for noise control depend upon the extent of the noise reduction required, nature of the equipment used and the economy aspects of the available techniques. MZCET/CIVIL/IV/CE6011/APM/5

5.5. Control of Noise Pollution contd…

Reduction in the noise exposure time or isolation of species from the sources form part of the noise control techniques besides providing personal ear protection, engineered control for noise reduction at source and/or diversion in the trajectory of sound waves. MZCET/CIVIL/IV/CE6011/APM/5

Noise Control at Source The noise pollution can be controlled at the source of generation itself by employing techniques like Reducing the noise levels from domestic sectors Maintenance of automobiles Control over vibrations Low voice speaking Prohibition on usage of loud speakers Selection of machinery Maintenance of machines MZCET/CIVIL/IV/CE6011/APM/5

Reducing the noise levels from domestic sectors: The domestic noise coming from radio, tape recorders, television sets, mixers, washing machines, cooking operations can be minimized by their selective and judicious operation. By usage of carpets or any absorbing material, the noise generated from felling of items in house can be minimized. Maintenance of automobiles: Regular servicing and tuning of vehicles will reduce the noise levels. Fixing of silencers to automobiles, two wheelers etc., will reduce the noise levels. MZCET/CIVIL/IV/CE6011/APM/5

Control over vibrations: The vibrations of materials may be controlled using proper foundations, rubber padding etc. to reduce the noise levels caused by vibrations. Low voice speaking: Speaking at low voices enough for communication reduces the excess noise levels. Prohibition on usage of loud speakers: By not permitting the usage of loudspeakers in the habitant zones except for important meetings / functions. Now-a-days, the urban Administration of the metro cities in India, is becoming stringent on usage of loudspeakers. MZCET/CIVIL/IV/CE6011/APM/5

Selection of machinery: Optimum selection of machinery tools or equipment reduces excess noise levels. For example selection of chairs, or selection of certain machinery/equipment which generate less noise (Sound) due to its superior technology etc. is also an important factor in noise minimization strategy. Maintenance of machines: Proper lubrication and maintenance of machines, vehicles etc. will reduce noise levels. For example, it is a common experience that, many parts of a vehicle will become loose while on a rugged path of journey. If these loose parts are not properly fitted, they will generate noise and cause annoyance to the driver/passenger. Similarly is the case of machines. Proper handling and regular maintenance is essential not only for noise control but also to improve the life of machine. MZCET/CIVIL/IV/CE6011/APM/5

5.6. Prevention of noise pollution
What is Pollution Prevention? "the use of processes, practices, materials, products, substances or energy that avoid or minimize the creation of pollutants and waste, and reduce the overall risk to the environment and human health" MZCET/CIVIL/IV/CE6011/APM/5

5.6. Prevention of noise pollution contd…
Construction of soundproof rooms for noisy machines in industrial and manufacturing installations must be encouraged. This is also important for residential building—noisy machines should be installed far from sleeping and living rooms, like in a basement or garage. MZCET/CIVIL/IV/CE6011/APM/5

Use of horns with jarring sounds, motorbikes with damaged exhaust pipes, noisy trucks to be banned. Noise producing industries, airports, bus and transport terminals and railway stations to sighted far from where living places. MZCET/CIVIL/IV/CE6011/APM/5

Community law enforcers should check the misuse of loudspeakers, worshipers, outdoor parties and discos, as well as public announcements systems. Community laws must silence zones near schools / colleges, hospitals etc. Vegetation (trees) along roads and in residential areas is a good way to reduce noise pollution as they absorb sound. MZCET/CIVIL/IV/CE6011/APM/5

Noise Pollution can come from cars, construction work, people yelling and anything that creates loud noise in the air. Some of the slogans Keep the noise down or the noise will keep you down. Noise can fill your ears, and put you in tears. Don’t be a clown, keep the noise down. Sometimes you say more by not saying anything at all. There is No Peace without Quiet. MZCET/CIVIL/IV/CE6011/APM/5

2 marks 1. What is noise? In simple terms, noise is unwanted sound. Sound is a form of energy which is emitted by a vibrating body and on reaching the ear causes the sensation of hearing through nerves. 2. How can noise affect us? Temporary Deafness: This Persists for about 24 hours after exposure to loud noise. Permanent Deafness: Repeated or continuous exposure to noise of around 100 dB results in permanent hearing loss. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 3. How can we control the Noise source? Reducing the noise levels from domestic sectors, Maintenance of automobiles, Control over vibrations, Low voice speaking, Prohibition on usage of loud speakers and Selection of machinery 4. What is the difference between sound and noise? Noise is unwanted sound. Sound is a form of energy emitted by a vibrating body and on reaching the ear it causes the sensation of hearing through nerves. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 5. List out typical sources of noise pollution. Source Noise level dB(A) Air compressors Quiet garden 110 KVA diesel generator 95 Ticking clock Lathe Machine Computer rooms Milling machine Type institute Oxy-acetylene cutting 96 Printing press MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 6. What is the purpose of frequency analysis? The frequency analysis allow to separate the main components of the signals by dividing the frequency range of interest into smaller frequency bands using a set of filters. 7. What are the impacts of noise? Physiological effects, Loss of hearing, human performance, Nervous system: Annoyance, Sleeplessness, Damage to material. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 8. What are the methods to control noise pollution? Identify the noise sources from each zone Find out the noise levels of each zone Compute Ldn values Identify the likely causes of noise from noise sources. Develop methodologies to solve the problem Attempt to solve 9.What are the noise exposure limits in a workspace environment? Regulations prescribe that, noise level of 90 dB (A) for more than 8 hr continuous exposure is prohibited. Persons who are working under such conditions will be exposed to occupational health hazards. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 10.What are the ambient noise limits? Sounds produced by all vibrating bodies are not audible. The frequency limits of audibility are from 20 HZ to 20,000 HZ. Noise generation is associated with most of our daily activities. A healthy human ear responds to a very wide range of SPL from - the threshold of hearing at zero dB, uncomfortable at dB and painful at Db. Due to the various adverse impacts of noise on humans and environment noise should be controlled. 11.Write short notes on Decibel, dB and Ldn DECIBEL is measurement unit of sound, represented by dB. The day night equivalent noise levels of a community can be expressed as -Ldn , MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 12.Write short notes on Infrasonic and Ultrasonic Infrasonic: The sound of frequency less than 20HZ. Ultrasonic: The sound of frequency more than 20,000 Hz 13.Equipment used in the measurement of noise levels Sound level meter Type-0 : Laboratory reference standard Type-1: Lab use and field use in specified controlled environment Type-2: General field use (Commonly used) Type-3: Noise survey Impulse meters For measurement of impulse noise levels e.g. hammer blows, punch press strokes etc MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 14.What is noise? Noise is defined as unwanted sound. A sound might be unwanted because it is loud, distracting, or annoying. 15.How is noise measured? Literally speaking, noise can't be measured directly, since there is no instrument for objectively detecting how "unwanted" something is. What can be measured is the sound level, a quantification of a sound's pressure or intensity and related to its loudness. Sound level is measured in decibels (dB), by a device called a sound level meter. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 16. What is a decibel? What are typical decibel levels of some common sounds? A whisper is 30 dB, conversational speech is 60 dB, and someone shouting at you from an arm's length away is 85 dB. Noise levelsof home appliances range from 50 dB (a refrigerator) to 95 dB (a food processor). Lawn equipment and power tools have noise levels of 80–120 dB. 17.How many decibels can the human ear handle? Immediate and irreversible nerve damage can be caused by sounds at 140 dB or higher (120 dB in young children). However, damage also occurs at lower sound levels, and this harm accumulates over time. Any sound above 85 dB can cause wear and tear on your ears that reduces your hearing acuity over time. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 18. What is the loudest sound possible? Sound is normally carried in air as a pressure wave. When the pressure of a sound wave becomes as high as the air pressure itself, the sound becomes a shock wave. Normal air pressure at sea level is 14.7 pounds per square inch (psi), or 101,325 Pascals (Pa), which is equivalent to 194 decibels (dB). So 194 dB is the loudest sound possible in air at sea level; beyond that point it becomes a shock wave. (Sound waves that are transmitted through water or other substances would have different limits.) 19. What are the effects of noise on human health? Noise has direct physiological effects such as hearing damage (including hearing loss and tinnitus, or ringing in the ears), as well as cardiovascular and hormonal disturbances. Indirect effects include sleep loss, interference with concentration and learning, mood changes and aggression, and social isolation. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 20. How does noise affect babies and children? Because the ear canal of a young child is smaller than an adult's, sound pressure is up to 20 dB greater than that in an adult ear. In addition to the threat to a child's hearing, noise causes physiological and mental stress, and significantly impacts learning and cognitive development. Background noise also interferes with speech perception and language acquisition. 20. What is "white noise"? White noise is a sound similar to radio static, or the sound a fan makes, that is often used to mask unpleasant sounds. Some people find it helpful for sleeping, and it can be a soothing sound for babies. MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 21.What are the most common sources of noise pollution? Worldwide, the most common sources of noise pollution are cars, trucks, and other motor vehicles. Planes and trains also contribute to noise pollution. Other sources include factory machinery, power tools, and construction equipment. 22.What problems does noise pollution cause for people? The World Health Organization (WHO) cites seven categories for the ways noise adversely affects human health: Noise-induced hearing impairment Interference with speech communication Sleep disturbances Cardiovascular and physiological effects Mental health effects Effects on performance of tasks Annoyance and effects on behavior MZCET/CIVIL/IV/CE6011/APM/5

2 marks contd… 24. What are the laws regarding noise pollution? Occupational noise is treated as a health and safety issue and is regulated at the state or national level in many countries. Community noise is typically regarded as a nuisance issue rather than a matter of health, and is normally regulated at local levels of government. The regulations and levels of enforcement vary widely across different communities, and worldwide. Noise-generating products such as automobiles and aircraft may be controlled by industry regulations, and building codes may set requirements for reducing sound transmission in new building construction projects. MZCET/CIVIL/IV/CE6011/APM/5

MOUNT ZION COLLEGE OF ENGINEERING AND TECHNOLOGY

Similar presentations

Presentation on theme: "MOUNT ZION COLLEGE OF ENGINEERING AND TECHNOLOGY"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

MOUNT ZION COLLEGE OF ENGINEERING AND TECHNOLOGY

Similar presentations

Presentation on theme: "MOUNT ZION COLLEGE OF ENGINEERING AND TECHNOLOGY"— Presentation transcript:

Similar presentations

About project

Feedback