Date:29/03/2006 URL: http://www.thehindu.com/2006/03/29/stories/2006032918130300.htm

Tamil Nadu - Chennai

Beware of those high decibels: your hearing and voice are at risk

R. Sujatha

Noise can impact not just on the ears but also the voice Noise affects different people in different ways and ENT specialists have valuable suggestions for every specific group.

Exposed to noise pollution. — Photo: K.V. Srinivasan

CHENNAI: Next time you increase the volume of your television or radio or speak louder because of the noise around you, remember that the noise will take its toll not just on your hearing but also on your voice.

Ear is sensitive

The human ear is sensitive enough to catch sounds from 0 to 140 decibels (db) or frequency range from 20 to 20,000 hertz. A whisper may be 0 db (15 hertz) while a normal conversation may hover around 60 db. All other typical sound frequencies range from 200 to 3,000 hertz. Sound at 140 db can severely affect nerves in the ear.

Traffic police at risk

In a typical situation, the din of traffic at road junctions can well be over 100 db and though the din is difficult to bear, a motorist, who waits to clear a signal, is not as badly affected as the traffic policeman.

Consider this: nearly one third of the 500 policemen tested among those manning traffic junctions had hearing problems, as a survey done by Chennai-based KKR ENT Hospital found three years ago.

"For people working in loud noise areas, deafness begins at 20,000 hertz and remains undiagnosed until it reaches 3,000 hertz. By then the damage has been done," says Ravi Ramalingam, consultant surgeon at KKR ENT Hospital.

But then, experts also note that working among loud noise can also lead to problems with one's voice.

"Normally, human voice tends to change due to age, hoarseness, breathlessness, fatigue and environment disturbances. Posture, weight, dental disorder, smoking, drugs, food such as milk, chocolates, spices, acid reflux, hearing loss, psychological well-being, endocrine dysfunction, surgery of the chest and abdomen can also affect one's voice," say specialists at the Department of Voice at the Foundation at Madras ENT Research Foundation (MERF).

Case in point

A person working in a noisy situation or at a noisy site tends to raise his or her voice. A case in point are professionals such as teachers, lawyers, politicians and singers who are all considered professional `voice users'. But even among them, classifications can be made according to their use of voice. Noise affects different people in different ways and ENT specialists have valuable suggestions for every specific group.

Singers among `abusers'

Singers, politicians and teachers are high on the `voice abusers' list, they note.

Elite voice users, such as actors and singers, should rehearse in a quiet atmosphere; but professional voice users such as teachers or lecturers must ensure that they use high quality sound system.

Safeguards

Lawyers, surgeons and businessmen are non-vocal professionals.

But factory workers and sales personnel are non-vocal non-professionals, who should keep away from extremely noisy places. Factory workers can mitigate abuse or damage by wearing earmuffs and sound attenuators at work place.

This can eventually save their voice too.