<i>May be more stressful than you realise</i>
An excessive noise level is a general threat to health and well-being. Although loud sounds like thunder storm are part of nature, in recent times big cities have become chronically very noisy. Even the towns are increasingly noisy.
This noise or sound pollution can damage our hearing capability. The risk of hearing loss increases as the noise becomes louder. This may happen so gradually and painlessly that one may not notice the minor wear and tear from one day to the next. In these types of cases, hearing aids only strengthen sounds and cannot restore normal hearing.
It has been found that a generous proportion of 'urban people' are at risk of Noise Induce Hearing Loss (NIHL), a condition caused by prolonged exposure to noise levels higher than 75 db. But dangers are not restricted to the ears only, it can set off the body's stress response and ultimately the body will deal with high levels of stress hormones (epinephrine, norepinephrine and cortisol).
German scientists found that there was a high risk of heart disease for anyone routinely exposed to sound levels over 65db. Another study in Kolkata discovered that 28 percent (a survey of more than 1000 people) suffered from hypertension due to traffic noises.
Exposed to excessive noise may cause the following problems —
- Fatigue, irritability, headache
- Elevated blood pressure
- Tinnitus (constant ringing sound)
- Poor sleep quality and cycles
- Increased susceptibility to minor infections.
The parts of the ear that process high frequency sounds are usually the first to be affected. The degree of hearing loss depends on the loudness of the noise and length of exposure. If your ears ring or sounds seem quiet afterwards, then the noise level was too loud and harmful. Sudden explosive sounds, such as gunshots or explosions can cause immediate damage.
Although sensitivity to noise varies from one individual to the next, experts consider that damage to hearing occurs when noise levels are higher than 85 db.
The loudness of sound is measured in units called decibels (db). For instance, typical sound level would be 35 decibels, a rock concert creats110-120 decibel, heavy traffic generates about 85-90 decibels and by 140 decibels sound becomes painful to our ear.
It is advised not to listen to noises of 109 db for any longer than two minutes at a time. Traffic noise is one of the most commonly experienced contributors to noise pollution. Most noise pollution comes from vehicles, especially buses, automobiles, trucks, aircraft (along airport) and some times loudspeakers. Construction equipments are sometimes dangerously loud. Some music appliances, when played at very high volume, particularly through personal headphones, are damaging ears.
In an Indian study, it has been found that the average age for age-related hearing loss has gone down from 70 years to 50 years, due to invisible factors like telephones (70 db), TV (75db), cell phones(68 db) and other day to day background sounds. Probably just living in a capital like Mumbai or Dhaka is enough to put one at risk addiction to iPods and cell phones accessories like handsfree gadget.
These need to be taken as serious issue. Much can be done to reduce the severity of the problem. In cities like Dhaka , governments should strict law and policy to counter noise pollution. Concerned authority need to make some warning against usage of loudspeakers.
We need more trees in our cities as trees are natural noise blocker. Individuals should get protected with earplugs particularly when noise levels exceed 85 decibels. Compressible foam ear plugs and earmuffs fitted correctly can reduce the intensity of sound reaching the eardrum by 10 to 25 db. It is better to set the volume of radio, TV, loud speaker, iPod at no more than 60 percent of its maximum.
Those who live in busy noisy areas need to put in carpets, hang heavy curtains and grow plants in verandas as much as possible to absorb noise. As well as 'Razuk' needs to take steps such as constructing sound barriers, insulating buildings, and restricting residential development in noisy areas.
The writer is a Healthcare Management Specialist and Visiting Professor of North South University (NSU), Dhaka, Bangladesh.
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