Noise pollution refers to the disturbing, unwanted or excessive sound that disrupts our peace of mind and interferes with our daily activities such as reading, sleeping, conversations etc.
It has been established that exposure to sounds of less than 70 dB is not harmful to hearing regardless of exposure time. On the other hand, exposure to sounds of more than 85 dB for over 8 hours is potentially harmful.
The damage done by sound levels ranging above 85 dB vary with time of exposure.
The physiologic changes produced by temporary exposure to noise are reversible. Whereas, exposure to noise of enough intensity and for sufficient duration can produce irreversible changes.
It is known that sound of low frequency is more disturbing and can have detrimental health consequences. Also, we are more annoyed when the noise increases progressively rather than when it remains constant.
Noise pollution is mainly caused by automobiles. In fact, they are the source of about 85% of all environmental noise. As the number of automobiles on our roads continue to increase, the extent of noise pollution is also increasing. The sound level of 140 dB is regarded as the threshold for pain. But this level is easily reached by automobiles today.
Airplanes and other aircraft also contribute to environmental noise.
Noise produced by industrial machinery is intrusive to people living in residential areas near industrial plants.
In some circumstances, human voices and animal sounds are also considered noise. However, they are not regarded as noise pollution.
Hearing impairment is caused majorly because of occupational exposure and recreational noise.Hearing loss causes loneliness, impaired speech, depression and impaired job performance. It presents challenges in communication, social development, academic performance and cognition. Noise-induced hearing loss may cause temporary or permanent tinnitus.
Noise reduces the ability to make sense of normal speech, concentration, and working capacity. It has been known to cause behavioral changes, irritation, confusion, and fatigue.
Noise pollution during night time makes it hard to fall asleep, wakes us up frequently and deprives us of a good night’s sleep. Uninterrupted sleep is vital if we want to have good mental and physical functioning. Disruption in sleep patterns causes mood changes, lack of concentration, decreased performance and alertness and can have long-term health effects.
Nocturnal noise can also have long-term psychosocial effects.
Noise has been assumed as a stressor which can trigger responses from endocrine and autonomic nervous systems which can have effects on the cardiovascular system and hence can be linked to cardiovascular disease.
Noise pollution can alleviate the symptoms of anxiety, nausea, emotional instability, mood swings, and stress.
Use of headsets, earphones, and speakers at dangerous volume levels is responsible for impaired hearing in the younger population.
People working in entertainment such as musicians and dancers are commonly at risk of noise-induced hearing loss.
Noise can diminish cognitive development in children. Children exposed to noisy homes and schools can have lower motivation and academic performance as noise interferes with learning, problem solving and attention.