Noise Pollution Quiz: Test Your Knowledge on Effects

Study Notes

Characteristics of Sound

Sound is not a substance that can accumulate in the environment like other pollutants.
It is measured in a unit called the 'Decibel' (dB).

Decibel Levels of Common Sounds

Threshold of hearing: 0 dB
Rustle of leaves: 10 dB
Broadcasting studio: 20 dB
Bedroom at night: 30 dB
Library: 40 dB
Quiet office: 50 dB
Conversational speech (at 1m): 60 dB
Average radio: 70 dB
Light traffic noise: 74 dB
Subway train: 90 dB
Symphony orchestra: 100 dB
Rock band: 110 dB
Aircraft takeoff: 120 dB
Threshold of pain: 146 dB

Effects of Noise Pollution on Physical Health

Exposure to high sound levels can cause physical damage to the ear and temporary or permanent hearing loss.
Temporary hearing loss is often called a temporary threshold shift (TTS).
People suffering from TTS are unable to detect weak sounds, but hearing ability is usually recovered within a month of exposure.
Permanent loss, called noise induced permanent threshold shift (NIPTS), represents a loss of hearing ability from which there is no recovery.
Exposure to 95 dBA for 8 hours every day for over a period of 10 years may cause about 15 dBA of NIPTS.
Noise can also cause harmful effects on the circulatory system by raising blood pressure and altering pulse rates.

Effects of Noise Pollution on Mental Health

Noise can cause emotional or psychological effects such as irritability, anxiety, and stress.
Lack of concentration and mental fatigue are significant health effects of noise.
Noise can interfere with normal auditory communication, mask auditory warning signals, and increase the rate of accidents, especially in industries.
It can also lead to lowered worker efficiency and productivity and higher accident rates on the job.

Permitted Noise Levels

Silent Zone: 50 dB (day-time), 40 dB (night-time)
Residential Zone: 55 dB (day-time), 45 dB (night-time)
Commercial Zone: 65 dB (day-time), 55 dB (night-time)
Industrial Zone: 70 dB (day-time), 70 dB (night-time)

Safe Time Limit for Exposure to Noise

A standard safe time limit has been set for exposure to various noise levels.
Beyond this 'safe' time, continuing exposure over a period of a year will lead to hearing loss.
Below a sound level of 80 dBA, hearing loss does not occur at all.
However, temporary effects are noticed at sound levels between 80 and 130 dBA.

Sources of Noise Pollution

Outdoor noise pollution: factories, vehicles, playing of loudspeakers during festivals
Indoor noise pollution: loudly played radio or music systems, and other electronic gadgets
Noise generated by firecrackers is much higher than the prescribed levels (125 decibels, as per the Environment (Protection) (second amendment) Rules, 1999).

Description

Test your knowledge on noise pollution, its measurement in decibels, the difference between sound and noise, and the harmful effects of exposure to high sound levels. Explore the various physical health effects caused by noise pollution.