DEAR ABBY: Several years ago, you printed several letters concerning older people who had heard music inside their heads. I would appreciate any information you can give me, because my 92-year-old mother is experiencing those symptoms and needs reassurance that she is not "going crazy."

Thank you for your assistance in this matter, and for many years of unadulterated information and pleasure. -- JUDITH PHILLIPS, R.N., CANYON, TEXAS

DEAR JUDITH: That problem continues to surface from time to time, and when I explain that it is not unusual, readers are greatly relieved to learn that they are not alone. Here they are again:

DEAR ABBY: Thank you for printing those letters from people who keep hearing music in their heads. I am one. I am now 76, and never told others because I was afraid of what they might think. I have been a nurse for more than 50 years and had never heard of this condition. I feared that maybe I was getting senile. I was truly relieved after reading in your column that many others had the same experience.

During my waking hours, I hear hymns and waltzes. All the waltzes I loved to dance to keep drifting through my mind. Now I can tell my doctor about it and not be afraid that he will look at me and think, "Poor soul. She is really failing!" -- EMILIE IN BUCKS COUNTY

DEAR EMILIE: You would not believe the number of letters from readers who had also been hearing things and doubted their sanity. One man said he nearly went crazy because he heard bees buzzing continually in one ear -- night and day. Another said he heard constant crackling sounds, like bacon frying. A woman heard the "chirping" of crickets. Still another said it sounded like a freight train was roaring through her head. All feared they were going mad.

The sounds are due to a condition called "tinnitus," but the musical hallucinations are yet another matter. Read on:

DEAR ABBY: It was interesting seeing all the letters sent to you by people with musical hallucinations.

The two cases I describe in my book, "The Man Who Mistook His Wife for a Hat," were rather rare and special examples of musical epilepsy associated with damage to the brain. But musical hallucinations are relatively common, especially in older people, and though they should be checked out, nearly always turn out to be benign -- a nuisance, but not necessarily a sign of neurological disease. Readers should be assured about this. -- OLIVER SACKS, M.D., PROFESSOR OF NEUROLOGY, ALBERT EINSTEIN COLLEGE OF MEDICINE, BRONX, N.Y.

DEAR ABBY: I'm in my late 60s and profoundly deaf. I also have a severe case of tinnitus, which is a chronic ringing sensation in my ears. My case is unbelievable. The sounds might be compared to a bad LSD trip without psychedelic visions. They sometimes last as long as four days.

Like most people, you will probably think I'm a nut case. I hear music or singing, or both -- the same compositions over and over. Would you be good enough to consult one of your authorities to verify the fact that I am not crazy? I believe that would be an otorhinolaryngologist. This small town does not have such a specialist. Hoping you can help me ... HEARING THINGS

DEAR HEARING: Write to: The American Tinnitus Association, P.O. Box 5, Portland, Ore. 97207. You will be referred to a specialist near you. Please enclose a long, self-addressed stamped envelope (75 cents) and $1 to cover the cost of their printed materials. It's a pittance to pay for peace of mind.

This one's for everybody, from teens to seniors. To purchase Abby's new booklet, "The Anger in All of Us and How to Deal With It," send a long, business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Anger Booklet, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)

DEAR ABBY: Several years ago, I read in your column about people having a problem with dry mouth.

I failed to keep the article in which you kindly offered information about my problem. Please print it again, and this time, I will make a note of the solution. I've read of other remedies, but I believe your information was the best. -- SPITTING COTTON

DEAR SPITTING COTTON: The column to which you referred was printed in October 1987, but here it is again:

DEAR ABBY: A while back you recommended a "saliva substitute" for people who suffer from dry mouth. Having suffered from that condition for two years, I went immediately to the pharmacy and asked for a saliva substitute. The pharmacist said she had never heard of such a product and told me to ask my dentist what the brand name was.

I called my dentist, and he had never heard of a saliva substitute either. Abby, can you tell me the name of this product and where it can be purchased? -- NEEDS IT IN ILLINOIS

DEAR NEEDS: I had no idea that the problem of "dry mouth" was so widespread until I mentioned it in my column and was promptly deluged with letters from readers seeking relief from that condition.

There are at least four brands of saliva substitutes on the market today. Ask your pharmacist to check the Annual Pharmacists' Reference Red Book, Facts and Comparisons, or Physicians' Desk Reference for Non-Prescription Drugs under "Saliva Substitutes."

Readers, for your information, "xerostomia" (dry mouth) can be caused by disease, medication, radiation therapy or the normal aging process. This condition can cause acute discomfort, tooth decay, inability to eat, swallow or talk, as well as difficulty in wearing dentures.

If your pharmacist has never heard of it and doesn't know where to get saliva substitutes, find another pharmacist.

DEAR ABBY: I am writing to thank you for an article that you ran recently that has given me more relief and comfort than I can describe.

I am 83, male and reasonably healthy, but in recent years I've been terribly troubled with a dry mouth -- especially at night. I complained to my doctor. He just shrugged his shoulders. Then I read your column in the San Francisco Chronicle, and my prayers were answered! In response to a letter asking why a person would use a mouth spray in public, you quoted a dentist who said that as a result of disease, medication, radiation therapy or simply aging, a number of people suffer from "xerostomia" (dry mouth).

I immediately phoned my druggist, and he had never heard of a saliva substitute, so I told him to call his supplier and order it.

He did, and the next day I picked it up and used it. Abby, I will be eternally grateful to you and that dentist. No more dry mouth! God bless you. -- GRATEFUL IN PARADISE, CALIF.

DEAR GRATEFUL: I'll print your letter for the benefit of others who suffer from dry mouth and are not aware of saliva substitutes.

Most teen-agers do not know the facts about drugs, AIDS, and how to prevent unwanted pregnancy. It's all in Abby's updated, expanded booklet, "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)

DEAR ABBY: I read with interest the letter from Dr. Marvin Leaf suggesting that the fact that a person has died from a smoking-related disease should be included in his or her obituary. But why stop there?

Since obese people are inclined to have high blood pressure and arteries clogged with cholesterol, making them prime candidates for fatal heart attacks, an obituary might read: "Harold H. Smith, age 57 and 55 pounds overweight, succumbed suddenly last Sunday from a fatal heart attack." (His cholesterol level and blood pressure could also be included here.)

And, because studies have shown that there is definitely a connection between breast cancer and dietary fat, the obituary of Mary Jones might read: "Mary Jones, whose passion for ice cream, butter and barbecued ribs proved to be truly a fatal attraction, died Monday after a long bout with cancer."

Also, let's not forget those who have died of AIDS. This is America; the people have a right to know! -- STUART M. JOHNSON, LONG ISLANDER

DEAR STUART: Thanks for an amusing piece of satire. Laughter is sometimes very close to tears.

DEAR ABBY: May I add a few words to the letter from "One Hopeless Guy" who decided to chew tobacco instead of smoke it?

Let me tell you what "dipping snuff" will do to you:

The nicotine from the tobacco seeps into your bloodstream, causing the arteries to constrict. The blood platelets become sticky, while the heart starts to pound. Since the heart is beating faster through narrowing arteries, the blood pressure rises, increasing the chances of heart disease and stroke.

While all of this is going on, the tobacco that has been stuffed between the cheek and gums is leaving a white lesion -- a precancerous condition that becomes malignant in from 3 percent to 5 percent of the cases. Your teeth will scream for a dentist, not to mention the fact that your chances for developing cancer of the lip, nasal sinus, pharynx, larynx and esophagus also increase.

Your sense of taste and smell are diminished, which could result in the excessive use of salt, putting you at risk for high blood pressure and/or kidney disease. Also, too much sugar may invite dental problems.

I know this is not pleasant, Abby, but people who dip snuff need to know the facts. -- RON JETTE, OTTAWA, CANADA

P.S. As my stationery indicates, I am director of communications of the Lung Association.

DEAR RON JETTE: On behalf of those who dip snuff -- or consider it the lesser evil to smoking -- I thank you.

DEAR ABBY: You told "Foolish and Sorry," an Orange County girl, that you knew of no way to remove tattooed eyeliner. There are, however, ways that ophthalmologists specializing in cosmetic surgery of the eye can remove permanent eyeliner.

"Foolish and Sorry" should contact the university eye center nearest to her to find out if there is an oculoplastic surgeon who is experienced in removing tattooed eyeliner. -- KATHLEEN F. LOUDEN, CHICAGO

Everything you'll need to know about planning a wedding can be found in Abby's booklet, "How to Have a Lovely Wedding." To order, send a long, business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Wedding Booklet, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)