It begins slowly. The first thing you may notice is the ringing in your ears and a feeling like they’re full. When you get into your car, the radio needs to be adjusted because it sounds lower than it did a few hours before — before the concert or gig or rehearsal, that is.

Most musicians do not get overly concerned — they’re used to it. Besides it always goes away after a day or two. Until one day you wake up and the tinnitus is still there and it has been a week.

Maybe it’s annoying enough to make you start looking on the Internet to see what it’s all about. Perhaps your doctor suggests that you get a hearing test. Somewhere deep inside your mind there is a voice telling you that those high notes are just not there anymore.

As an audiologist who specializes in hearing conservation for musicians, the above scenario is all too familiar to me.

What happens is that after an exposure to loud music, there is a temporary shift in hearing thresholds. In other words the level at which you can hear a sound has shifted and is not as low as it had been prior to the exposure. You have lost some hearing temporarily.

In about 16 to 18 hours — certainly within 48 — the hearing will go back to its original level.

However, in time, with repeated exposures, the loss remains and hearing thresholds stay at the higher level. The temporary threshold shift has become a permanent threshold shift. You now have hearing loss. The microscopic hair cells of the cochlea have been damaged or destroyed.

When a group of hair cells die so does the electrical impulses for that frequency range. You can think of it as a broken key on a piano. The damage is usually greatest in the high frequencies since that is where the cochlea is most vulnerable. Once the hair cells are damaged there is no undoing it. Dead hair cells do not resurrect.

Music induced hearing loss is insidious. It creeps up on you slowly and progressively. The level of the music and the length of time you are exposed to it will determine the rate at which hearing loss is incurred and how fast it will worsen. The question then is: How loud can the music be before you are at risk for hearing loss?

There are a number of tables that have been used to determine this. I think the simplest approach is the five decibel rule.

According to OSHA, the average person may be exposed to 90 decibels of music for eight hours without risking damage to his or her hearing.

However, for each increase of five decibels the time allowance gets cut in half.

Therefore, if you can stand 90 decibels for eight hours, then you can stand 95 decibels for four hours, and so on.

This guideline assumes that there is no other exposure to sound levels that exceed the amounts specified. This is because noise exposure is multiplative.

For instance, a typical day for a musician may include a rehearsal as well as a performance. Additionally, if, after a gig, you hop on a motorcycle, go home and use a chainsaw, you are obviously increasing your exposure time.

There are further considerations such as the instrument that is played (as some are louder than others), what kind of music is being performed, and your position on stage in relation to other performers.

Before you give up music for fear that you are going to be deaf in the not-too-distant future, let me assure you that hearing loss is not inevitable. Although it is true that you are at greater risk, there are steps that you can take to lower it.

If you consider that sound levels at concerts have been measured at 130 decibels, the value of some kind of attenuation becomes obvious.

I think one of the most effective methods for reducing sound levels is the consistent use of musician’s earplugs. (These are custom-made earplugs, not the over-the-counter variety.)

The major advantage is that custom plugs attenuate all the frequencies equally, thereby maintaining the integrity of the music.

(The generic variety attenuates the lows more than the highs, resulting in a muffled reduction in sound.)

Custom earplugs are made with a deep seal insuring that you do not get that hollow, echo-like sound. And because they are made to fit your ears they’re more comfortable and remain in place.

Additionally, I would recommend that you avoid exposure to sounds exceeding 90 decibels. Increase the distance between you and high-intensity sounds. Try to give your ears a rest by taking a break from the music whenever possible. And finally, have your hearing evaluated by a licensed audiologist on a yearly basis to ensure protective measures are working.

Dr. Silver has worked with many well-known performing artists. You may contact her at VickiHearing@yahoo.com.

FREE HEARING TESTS AT LOCAL 802

Since 2001, Local 802 and the Local 802 Health Benefits Fund have offered free hearing tests for members. The tests are conducted by audiologist Dr. Ellen Kelly utilizing a professional booth that was specially designed and installed in the union’s Room B in 2001.

Dr. Kelly, who served on the board of the Irving Selikoff Center for Occupational and Environmental Medicine at Mt. Sinai Hospital, has a wealth of experience in dealing with hearing-related issues. In addition to the testing, she also provides consultations on hearing protection.

The next test is May 23 from 9 to 5 at the union. For more information or to schedule an appointment, call Tara Donach at (212) 245-4802, ext. 101.