Effects of Noise Pollution

Noise can disturb our work, rest, sleep, and communication. It can damage our hearing and evoke other psychological, and possibly pathological reactions. Given below are some of the adverse health effects of noise pollution:¹

Hearing Loss

Hearing loss can be either temporary or permanent.

• Noise-induced temporary threshold shift (NITTS) is a temporary loss of hearing experienced after a relatively short exposure to excessive noise.

• Noise-induced permanent threshold shift (NIPTS) is an irreversible loss of hearing that is caused by prolonged noise exposure. NIPTS occurs typically at high frequencies, usually with a maximum hearing loss which occurs around 4000 Hertz.

Both these losses may occur along with presbycusis, which is a permanent hearing impairment that happens with our natural aging process.

Interference with Communication

Noise interferes with speech communication. If both noise and speech are simultaneous, then one of the two sounds makes the other one inaudible. An important aspect of communication interference happens in:

• Occupational situations where the failure of workers to hear warning signals or shouts may lead to injury.

• In offices, schools and homes where noise is a major source of annoyance.

Disturbance of Sleep

Noise intrusion can cause difficulty in falling asleep and can awaken people who are asleep, especially young infants, older people, etc.

Annoyance

Noise annoyance may be defined as a feeling of displeasure evoked by noise. The annoyance-inducing capacity of a noise may happen over time also. For example, if the loudspeaker plays near your house for more than 1 month, then over time you may be annoyed. However, reactions to noise differ person to person depending on many factors, such as sensitivity to noise, etc. For example, you may be able to tolerate noise from a speaker near your house but your grandparents may be more sensitive to noise.

Effect on Performance

Noise can change the state of alertness of an individual and may increase or decrease efficiency. For example mental activities involving vigilance, information-gathering and analysis may be affected by noise.

Physiological Effects

Noise has an explicit effect on the blood vessels, especially the smaller ones known as pre-capillaries. Overall, noise makes these blood vessels narrower. Noise causes the peripheral blood vessels in the toes, fingers, skin and abdominal organs to constrict, thereby decreasing the amount of blood normally supplied to these areas. Blood vessels which feed the brain, dilate in the presence of noise. This is the reason why headaches result from listening to persistent high noise. Some health problems which may occur include:

• Galvanic skin response. In other words, changes in the body originating from sweat glands in the skin that reflect the intensity of an emotional state.
• Increased activity related to ulcer formation. Prolonged chronic noise can also produce stomach ulcers as it may reduce the flow of gastric juice and change its acidity.
• Changes in intestinal motility which is the movements of the digestive system, and the contents within it.
• Changes in skeletal muscle tension. In other words, the force generated by the contraction of muscles changes.
• Subjective response irritability perception of loudness
• Increased sugar, cholesterol and adrenaline
• Changes in heart rate
• Increased blood pressure
• Vasoconstriction. In other words, the constriction of blood vessels which increases blood pressure.

Noise not only causes harmful consequences to health while being awake. It also effects when the body is asleep or unaware.²

Stress

Noise may cause stress in any number of ways, including headaches, irritability, insomnia, digestive disorders, and psychological disorders. For example, frequent exposure to excessive noise cause tiredness.

Effect on Unborn Babies and Children

The foetus is not fully protected from noise. Noise may threaten foetal development, like affecting the birth weight. Levels of noise which do not affect adults may interfere significantly with children as they are more sensitive. Reading ability, speech, language, and language-related skills of children may be affected due to noise pollution.

1. Noise Pollution (V), In re, (2005) 5 SCC 733. [↩]
2. Noise Pollution (V), In re, (2005) 5 SCC 733; Noise Effects Handbook: A Desk Reference to Health and Welfare Effects of Noise, by Office of the Scientific Assistant, Office of Noise Abatement and Control, US Environmental Protection Agency, October 1979. [↩]