Only rarely do I see a musician in my audiology clinic who does not have a temporary threshold shift (also known as TTS). This is especially true of classical musicians who perform 7 times a week (with Mondays off but three shows on the weekend- two evenings and a matinee), rehearse and practice several hours each day, and teach several hours each day. And on top of that, like everyone else, they listen to their MP3 player and even occasionally mow their lawns.
Rock and jazz/blues players have slightly less exposure to noise and music, but typically they are not far behind their classical cousins in their dose of exposure.
TTS lasts for 16-18 hours, but this is only for the temporary shift in their audiometric thresholds. The musicians may still suffer from the effects of tinnitus for several days after an exposure. Every musician I see is still suffering the temporary effects of some sort of music or noise exposure. Waiting for a musician to be away from music for 16 to 18 hours so that I can get a “valid audiogram” is frequently unrealistic.
So, if TTS is so prevalent with musicians, why even bother testing their hearing? That’s a really good question. Part of the answer is historical, part is financial, and part is educational. Very little, however, is diagnostic.
The historical portion is best described as “inertia”- we always test hearing, so why not now? The financial part is that depending on the jurisdiction and the various regulations in your state, province, or country, there is remuneration for doing a hearing test. And the educational aspect is well,…, educational. And it’s the educational aspect that I find most important.
It certainly is not diagnostic. TTS is not a predictor of permanent threshold shift (PTS). That is, a person who is susceptible to large amounts of threshold shift is not any more, nor any less, susceptible to future permanent hearing loss than anyone else. Our intervention would not differ if there was a 25 dB HL loss at 4000 Hz in one person and a 35 dB HL loss in another. This should not be surprising given the various and differing physiological and biochemical processes that occur. TTS has several etiologies, but the primary one is Glutamate ototoxicity. High levels of glutamate that are created with higher noise and music levels can be toxic. It takes 16-18 hours to rid the ear of this excessive amount of neurotransmitter substance. In contrast, permanent hearing loss is brought about by either passive cell death (apoptosis) or dramatic cell destruction, which has consequences for an entire region of hair cells (necrosis). Different effects for different processes.
In any event, our intervention would be pretty much the same- counseling about hearing protection; counseling about environmental changes; and counseling about moderation and other ways to minimize non-music noise exposures.
It would be interesting to be back in Dr. Raymond Carhart’s laboratory in the 1940s. Imagine if he had the technology of the current era and today’s understanding of the auditory system. I am pretty sure that he would not have dwelt on acuity tests such as pure tone audiograms. I suspect that Dr. Carhart would have used otoacoustic emission (or other types of functional) testing and would have spent most of his time looking at the acoustic environment and how that can be altered. In turn, any funding sources for an audiological evaluation would have been based more on function and environmental assessment than on acuity testing.
An alternate future is not just a great science fiction concept. We live in the future now. We have everything that Dr. Carhart would have ever wanted. We just need to use it better than we do.
I routinely perform pure tone testing because I have always performed pure tone testing! I can do a pure tone audiogram in my sleep- I don’t even need to calculate masking levels- I just “intuitively” know it. The audiogram is such a poor description of auditory reality, but having said that, let me add that hearing loss looks so “obvious” when it is recorded on an audiogram. That makes pure tone testing a wonderful device to convey information to the client and musician- “Here is where you are; and here is what a ten year old kid has”.
The bottom line is that when working with musicians, I spend most of my time counseling and looking for valid measures of auditory function- not auditory acuity. I do assess auditory acuity, but it consumes very little of my effort and clinic time. Gradually I am unlearning the bad lessons of the past and starting to learn new habits- habits that hopefully will improve what I can do for the musician.