Malcka Razovsky Stern is a communicator. She always has been a witty raconteur, an accomplished conversationalist and, at nearly 91, she retains her faculties -- as they say -- pretty much intact. All, that is, except one: her hearing.

Her loss of hearing has been progressive and relentless over the last decade or so and although she has been fitted with the latest in hearing aids, plus stereo earphones for her television and a sound-magnifying gadget on her telephone, she is increasingly being cheated of what used to be one of the chief joys of her life -- socializing.

Malcka Stern is one of an estimated 20 million Americans with some hearing loss. According to Henry Tobin, an audiologist at the Fort Howard VA Hospital near Baltimore, hearing loss in the aged is usually caused by two major factors: Accumulation of noise damage to the auditory nerves, and changes in the blood circulation to the ear. It is not inevitable, but it is common.

Recently, Mrs. Stern, a widow, joined a writing group for people over 65 -- everybody else, she says, is 66 -- which meets at her quasi-independent-living for senior citizens apartment house in Madison, Wis. She also belongs to a support group for hearing-impaired run by the communications department of the University of Wisconsin.

For both groups, she wrote an essay, from which this is exerpted:

At dinner the other night one of the residents leaned over and whispered in my good ear: "Be sure to come to the Happy Hour tomorrow. It will be a great party and just think, free sherry." I hesitated to accept the invitation, but on the other hand I love being with people and I do get tired of my own inescapable company. So against my better judgment I decided to go, although I should have known better.

You may ask why.

My hearing aid exaggerates all sound, particularly unpleasant ones.

A chorus of ordinary human voices becomes a nightmare of screaming demons which take possession of me, even altering my normal behavior. I become completely discombobulated.

. . . I arrived at the party, which was already in full swing, planning not to stay too long. The clamor was already unbearable.

Like bombs bursting in air, trains rushing through tunnels, screech upon screech.

I found myself shakily standing beside a table stacked with beautiful food, grabbed a plate, piled on it lots of goodies, remembered to pick up a glass of punch (I am not a sherry drinker), and I laboriously plopped myself in a vacant chair next to a bright and helpful gentleman.

All the time the babel and racket grew worse and worse. As I sat down, food from my tray kept sliding to the floor and my seat mate (whose name I suddenly forgot, although I know it as well as my own) chivalrously picked it up -- an olive here, a slippery mushroom there. Embarrassed beyond words, I tried to make conversation and addressed him first as Mr. Baxter and then again as Mr. Dixon, so he probably and justly thinks I am off my rocker.

Please, Mr. Baker, forgive me.

However, I did remember that he takes professional photographs and, still bent on being sociable, . . . I asked if he had put his pictures in an album and I actually heard his voice when he answered, "There are several volumes of my pictures in the Family Room," which was not far from where we were sitting.

Then I had an inspiration. In just a moment I could escape from the torture of the din. I sprang out of my chair and said to him: "I am going to look at your pictures at once," and I fled to the Family Room down the hall. Then, when it was no longer necessary, I turned off my hearing aid and uttered a prayer of thanks for the beautiful silence.

"What is so important," says Malcka Stern, "is to convince the people who make hearing aids to concentrate less on making them unobtrusive, and more on making them useful, doing something about that backwash of extraneous sound."

Specialists like Tobin agree that in the effort to miniaturize hearing aids "for cosmetic reasons," advances in electronics that could enhance quality were ignored.

Indeed, many deaf people do not admit to their disability, adding to an already distorted public image of the hearing impaired the suggestion of slight battiness.

Dorothy Hayes, a clinical instructor in the University of Wisconsin's Department of Communicative Disorders, and leader of the Madison support group to which Mrs. Stern belongs, says that "often, people resort to little strategies that they've developed such as nodding their heads and smiling. That works just wonderfully for letting the other person know they can go on and on and on, but it does have its limitations."

To end the hearing-aid caused cacophony, some researchers and audiolT ogists are devising electronic gadgets -- to be used in conjunction with hearing aids -- that can enhance the hearing aid's usefulness. Some can diminish background noise without affecting conversation.

They vary in cost from about $40 to about $1,000 for FM wireless assemblies. For most of his patients Tobin uses a system of inexpensive components mostly from Tandy Corp.'s ubiquitous Radio Shack stores. It consists of an amplfier (ask for Archer 200 mW amplifier/speaker, No. 277-1008B -- about $11), a lapel microphone that can be handed back and forth (No. 33-1052, $9.95), a nine-volt battery to run the amplifier, and a neck loop.

The loop is the only component that must be ordered separately. Specify: "the 11-inch diameter neck loop to be matched to the Radio Shack amplifier," Tobin says. To get it, write to Lionel Rainman, 2316 185 Pl. NE, Redmond, Wash. 98052. The loop is $14 and may take six weeks to arrive.

The total package costs about $40, says Tobin, and "you can talk even with a rock 'n' roll band right there. It can also be used for small group meetings because for a few dollars more you can get a dual jack adapter and put two mikes on it. You can have two or even three people talking, and the hearing-impaired person can follow what is going on. We've used it in factories where it has even permitted a hearing-impaired supervisor to stay on the job."

Caveats: Such gadgets are adjuncts to hearing aids, not substitutes. Indeed, to use them one must have hearing aids equipped with a telephone or "T" switch. It is recommended that before buying the components those interested find a consumer group or audiologist who can assist in assembling and learning how to use the device.

Tobin, who is a professional adviser to the Consumer Organization for the Hearing Impaired (COHI), which has just affiliated with the National Association for Hearing and Speech Action (NAHSA), warns that some training is essential to optimum use of even a hearing aid. "It's just not enough to sell an aid and tell the person to go out and use it."

Meanwhile, Malcka Stern, who is the mother of the Healthtalk columnist, speaks out for her afflicted fellows, even if they only nod and smile when she does so. Resources

For information on where to find devices and how to use them, write National Association for Hearing and Speech Action and Consumers Organization for the Hearing Impaired, 10801 Rockville Pike, Rockville, Md. 20852. Phone 897-8682. (Outside Washington Metropolitan area call 1-800-638-TALK, voice or TTY.)