Miraculous Instrument

Seven and a half million people in the U.S. are deaf or hard of hearing. A lot of them would hear and feel much better, doctors say, if they wore a hearing aid. Thanks to recent improvements in such aids, and to large-scale studies of hearing during World War II, ear specialists now take a more hopeful view about deafness than they used to.

Some of the hopeful new findings were reported last week in a book called Hearing and Deafness: A Guide for Laymen (Murray Hill Books; $5). The authors are a group of topflight experts headed by Dr. Hallowell Davis, longtime Harvard physiologist, now research professor of otolaryngology at St. Louis' Washington University.

The Unreal World. One of the things that impressed the doctor-authors in their wartime study of thousands of deaf G.I.s was that the hazards of deafness are largely mental. Their book vividly pictures how it feels to be deaf:

"The door makes no noise as you close it after you and step out on the sidewalk. A heavy rain is falling silently. Five o'clock traffic is jamming the street; people are crowding past you, but you hear no sound. Newsboys in front of the building are arguing angrily over something, but you can only see the exaggerated movement of their lips as they shout at each other. ... Everything moves with the unreality of pantomime.

"When you reach home, you see your family's smiles of greeting, you see their lips move, but the rich experience of hearing the tone and rhythm of their familiar voices is lost. . . . The deaf man . . . misses the snatches of talk normally overheard as we ride the subway ... the tick of a clock . . . vague echoes of people moving in other rooms in the house . . . [the] incidental noises [which] maintain our feeling of being part of a living world. ... He feels as if the world were dead."

Beaten down by loneliness, the hard-of-hearing tend to be irritable and depressed about their trouble. Davis & Co. think that there is no reason to be so gloomy; modern medicine has minimized the handicap of poor hearing.

The Terrible Racket. The human ear, Dr. Davis observes, is a miraculous instrument. It is normally so finely tuned that it

responds to faint sound waves whose power is measured in quadrillionths of a watt. "The human ear is actually so sensitive that at its best it can almost hear the individual air molecules bump against the eardrum in their random thermal flight."

"The wonder," says Davis, "is not that our ears sometimes fail us, but rather that they stand the racket as well as they do." At 120 decibels (the noise of a nearby plane engine), the ear begins to feel uncomfortable; at 130 decibels, it tickles; at 140 decibels (near a powerful air-raid siren), it hurts, and grows temporarily deaf. But even a shattering noise rarely causes complete deafness. The commonest causes of deafness (besides old age) are 1) inflammation of the middle ear (otitis media), usually due to a head cold; and 2) a bony growth in the middle ear (otosclerosis), a hereditary disorder that usually attacks in childhood.

Is Deafness Curable? Yes, say the doctors, if the nerves have not been damaged. By surgery and other methods, ear specialists can often eliminate the middle-ear defect that impairs hearing. Davis & Co. give guarded approval to the promising "fenestration" operation (successful in 75% of cases when the nerves are intact). In this operation, the surgeon creates a by-pass around an ear obstruction by cutting a "window" in adjacent bone and grafting over it a flap of skin to protect the inner ear. The operation sometimes fails because bone grows back over the window.

But in many cases, deafness is helped by a hearing aid. In mild cases, the doctors point out, all the patient really needs to do is stick a button attached to a shoestring in his ear; people will take the hint and speak up.* A hand cupped behind the ear also improves hearing substantially (as much as 10 decibels). If the hearing loss is 35 decibels or more (normal speech: 65 decibels), the patient needs an electrical hearing aid. Some 800,000 people in the U.S. now use such aids.

Dr. Davis and colleagues offer many a useful tip to hearing-aid users--and to all the people who talk to them. Best tip to the non-deaf: don't shout. A hearing-aid wearer, like most deaf oldsters, is just as sensitive to loud noises as anybody else--if not more so.

* Deaf Beethoven used a hearing aid of a sort: a stick with one end held in his teeth and the other pressed against the keyboard of the piano.

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