ILL- EFFECTS OF NOISE POLLUTION
➢ Noise is unwanted sound.
➢ Some physiological disturbances are:
1. Loss of hearing: The most common ill-effect of noise pollution is impairment
of hearing ability of an individual.
• Hearing ability of an individual is monitored by Audiometric Tests.
• Audiometric Tests is the most common technique of which is
referred to as threshold technique, based on determination of the
minimum sound level which an individual can hear.
• Starting from a zero value the sound level is gradually raised.
• The level of sound which is an individual can just perceive is noted.
• This is followed by gradual lowering of volume of a louder sound and
the level of sound which is no longer audible to subject is recorded.
• An average of the two values taken as the threshold of hearing
individual concerned.
• The auditory system recovers itself when the exposure is ceases.
• In audiometric tests, the phenomenon is referred to as Temporary
Threshold Shifts or TTS.
2. Other health effects of noise pollution: Loud noise is a nuisance which
affects sleep, concentration and work or performance of an individual.
• Optical system is affected by noise pollution.
• Dilation of pupils, impairment to night vision, decrease in colour
perception ability.
• Noise affects our cardiovascular system.
• Loud noise tends to decrease the output of blood from heart cause
arterial blood pressure to fluctuate and smaller blood vessels of the
body constrict reducing the flow of blood to the organs.
• Eosinophilia, hyperglycemia, hypokalaemia caused by changes in
blood circulation and other body fluid due to noise pollution.
PREVENTION AND CONTROL OF NOISE POLLUTION
➢ Loud noise is the form of pollution causes much public concern.
➢ Necessary steps have to be taken to control the nuisance.
➢ Some of these are:
1) Reduction of noise at the source of its origin: A little precaution can
reduce much of the nuisance caused by loud noise.
• Noise levels can be reduced by replacement of noisy and rattling
parts, providing better cushioning to check the vibrations, proper
oiling and greasing to smooth running and using effective silencers.
2) Application of sound proofing techniques to muffle down loud noises:
• Sound waves are absorbed by porus material (perforated sheets and
other objects).
• Putting cotton plugs in the ears reduces noise level for the individual
concerned, sound barriers placed around the source of origin of loud
➢ Noise is unwanted sound.
➢ Some physiological disturbances are:
1. Loss of hearing: The most common ill-effect of noise pollution is impairment
of hearing ability of an individual.
• Hearing ability of an individual is monitored by Audiometric Tests.
• Audiometric Tests is the most common technique of which is
referred to as threshold technique, based on determination of the
minimum sound level which an individual can hear.
• Starting from a zero value the sound level is gradually raised.
• The level of sound which is an individual can just perceive is noted.
• This is followed by gradual lowering of volume of a louder sound and
the level of sound which is no longer audible to subject is recorded.
• An average of the two values taken as the threshold of hearing
individual concerned.
• The auditory system recovers itself when the exposure is ceases.
• In audiometric tests, the phenomenon is referred to as Temporary
Threshold Shifts or TTS.
2. Other health effects of noise pollution: Loud noise is a nuisance which
affects sleep, concentration and work or performance of an individual.
• Optical system is affected by noise pollution.
• Dilation of pupils, impairment to night vision, decrease in colour
perception ability.
• Noise affects our cardiovascular system.
• Loud noise tends to decrease the output of blood from heart cause
arterial blood pressure to fluctuate and smaller blood vessels of the
body constrict reducing the flow of blood to the organs.
• Eosinophilia, hyperglycemia, hypokalaemia caused by changes in
blood circulation and other body fluid due to noise pollution.
PREVENTION AND CONTROL OF NOISE POLLUTION
➢ Loud noise is the form of pollution causes much public concern.
➢ Necessary steps have to be taken to control the nuisance.
➢ Some of these are:
1) Reduction of noise at the source of its origin: A little precaution can
reduce much of the nuisance caused by loud noise.
• Noise levels can be reduced by replacement of noisy and rattling
parts, providing better cushioning to check the vibrations, proper
oiling and greasing to smooth running and using effective silencers.
2) Application of sound proofing techniques to muffle down loud noises:
• Sound waves are absorbed by porus material (perforated sheets and
other objects).
• Putting cotton plugs in the ears reduces noise level for the individual
concerned, sound barriers placed around the source of origin of loud
