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BES222 Environmental Engineering Eng’r . Cynthia S. Macariola Instructor

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Noise Pollution is a type of energy pollution in which distracting, irritating, or damaging sounds are freely audible. Noise pollution contaminants are not physical particles, but rather waves that interfere with naturally-occurring waves of a similar type in the same environment. Noise Pollution can be defined like the excess of sound that disrupts the normal conditions of the environment in a certain area.

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Sounds are considered noise pollution if they adversely affect wildlife, human activity, or are capable of damaging physical structures on a regular, repeating basis. In the broadest sense of the term, a sound may be considered noise pollution if it disturbs any natural process or causes human harm, even if the sound does not occur on a regular basis.

A noise problem generally consists of three inter-related elements: :

A noise problem generally consists of three inter-related elements: the source the receiver the transmission path

Basis of Differentiation:

Basis of Differentiation the habit and interest of the person/species the ambient conditions impact of the sound &


Measuring Sound and Noise

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The intensity of sound is measured in sound pressure levels (SPL) and common unit of measurement is decibel, dB .

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The decibel (dB) is a measure of sound intensity; that is, the magnitude of the fluctuations in air pressure caused by sound waves. Decibels are usually measured with a filter that emphasizes sounds in certain frequencies. This filter is called sound level meter . Normal conversation is around 60 dB. Noise of less than 75 dB, even for long periods, Is unlikely to damage your hearing.

Damaging Levels of Sounds:

Damaging Levels of Sounds SOURCE SOUND IN DECIBEL EFFECTS Rocket Launching 180 Danger Level Gunshot 140 Danger Level (threshold of pain) Jet 130 Cause Damage: 3.5 min/day Car Horn 120 Cause Damage: 7.5 min/day Night Club 110 Cause Damage: 30 min/day Lawnmower 105 Cause Damage: 1 hr /day Truck / Scream 90 Cause Damage: 8 hr/day Alarm Clock 80 annoying

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SOUND INTENSITY Soft whisper 30 dB Normal conversation 50 – 60 dB Subway, city traffic, alarm clock, and factories 80 dB Chainsaw, stereo headphones, and nightclub 100 dB Sound at rock concert (in front of speakers) 120 dB Gunshot or jet plane 140 dB Rocket launching 180 dB Examples of Sound Levels

Different Noise Frequencies:

Different Noise Frequencies

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What are the sources of NOISE POLLUTION?


Includes: movement of utensils, cutting and peeling of fruits/vegetables, etc . DOMESTIC


Includes: shores, birds/animal shouts, wind movement, sea tide movement, water falls, etc. NATURAL


Includes: vendor shouts, automobiles, airplanes, marriages, laboratory, machinery, etc. COMMERCIAL


Includes: generator sets, boilers, plant operations, trolley movement, transport vehicles, pumps, motors, etc. INDUSTRIAL

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Why do we need to bother about NOISE POLLUTION?

The Human Ear:

The Human Ear

Noise and Human Hearing :

Noise and Human Hearing Actually hear with our brain, not our ears. Hair cells send impulses to brain Hair cells are extremely delicate Damage to hair cells can result to hearing loss. Threshold shift-several hours Trauma permanent Noise induce gradually become permanent

Effects on Humans:

Effects on Humans Auditory effects interfering with hearing . auditory fatigue and deafness Non- auditory effects interfering with social behaviour . problems with communications , sleep , recreation , mental equilibrium ( peace ), and the ability to concentrate at work Physiological effects affecting biological functions . anxiety , neurosis, insomnia , dizziness , nausea, fatigue, visual symptoms , hypertension , cardiovascular symptoms , liver changes , nervous symptoms , changes in skin , fast irregular heart beats ( tachycardia )

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Endocrine and hormonal changes relating to stress and noise levels . raised adrenaline and cholesterol . Noise causes blood vessels to close cutting down blood supply to the fingers and toes. Respiratory changes occur due to noise . Psychological effects . physical and mental fatigue, loss of concentration , lower efficiency , reduced output, absenteeism , higher rates of accidents , behavioural changes , errors at work , loss of sleep , psychosomatic disorders , diseases related to stress, mental illness , aggravation of existing stress problems and mental illness , neurotic effects , rage anger , crime

Effects on Wildlife:

Effects on Wildlife Reduced migration of birds and other animals . Loss of food habitats if animals are driven away . Animals in city zoos tend to become lethargic and their health deteriorates .

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Animals tend not to reproduce, which threatens their survival . Other effects include duodenal ulcers , atrophy of the thymus gland , and changes to adrenal glands .

Effects on Structures:

Effects on Structures Physical effects from noise include : vibration to buildings , damage to glass windows , plaster cracking, damage to building foundations .

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How can we prevent NOISE POLLUTION?

Control of Noise Pollution:

Control of Noise Pollution The techniques employed for noise control can be broadly classified as : Control at source. Control in the transmission path. Using protective equipment.

Measures Against Noise Pollution :

Measures Against Noise Pollution 1972 Noise Control Act - responsible for researching and regulating noise pollution. As of 2006 noise pollution is now considered an environmental problem. Road development and urban planning take into consideration the amount of noise they will produce. Communities have enacted anti-noise ordinances.

What is Being Done?!:

What is Being Done?! Engineers have developed better methods of using technology that produce less sound. In Japan, the Yokohama Tire Company has introduced a high performance tire that reduces sound. Companies are also creating new devices that are “anti-noise”. It works by emitting a sound wave that matches exactly the noise’s sound wave so that the waves can cancel each other out.

Other Countries Against Noise Pollution :

Other Countries Against Noise Pollution Bolivia Ecuador Venezuela Spain

Terri Alphon A. Yee:

This presentation was brought to you by: Terri Alphon A. Yee Sheila Mae G. Alonzo Carmela Fe C. Mañgao EcET2A SY 2010 - 2011 Thank you!!!

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