I am constantly amazed by how similar the hearing of an 85-year-old who has never been exposed to noise and has never seriously played music is to the hearing of an 85-year-old retired professional clarinet player who sat down-wind of the trumpet section for more than 45 years.
If their hearing was measured when these two fellows were in their 40s, I suspect that the musician would have had greater hearing loss on an audiogram than did his non-musical colleague, but something happens in the last several decades of life that frequently covers up this noise or music-exposure history. It’s as if presbycusis (hearing loss associated with aging) becomes a much more dominant factor in the later years than music or noise exposure.
This phenomenon is nothing new, and it is well known by people who study large hearing loss data bases, also known as noise exposure “models”. The effects of presbycusis appear to swamp the effects of other causes that affect the inner ear. Some have referred to this as “asymptotic hearing loss,” meaning that over time, the deterioration still continues but gradually becomes less and less. The greatest change from noise or music exposure may happen in the first 10-15 years of exposure and then only more incrementally after that.
We are not sure of the reasons for this but I can think of many possibilities ranging from auditory toughening, biochemical changes, the nature of damage to the cochlear hair cells, and so on. I am not sure that something as multi-factorial as this phenomenon will ever be pinned down.
Nevertheless there are some things that we can still share with our clients, and here is what I usually say when they visit me clinically:
- The audiogram is a very simple and gross measure. Even though you have suffered some permanent hearing loss, this may still be only the tip of the iceberg. This imparts at least a partial understanding that a normal audiogram doesn’t necessarily mean “normal” auditory function and that there are many locations in the auditory pathway(s) where subtle pathologies may occur.
- Just because you already have some nerve damage in your cochlea caused by all of your music, you are no more, nor less susceptible than anyone else to future hearing loss. This is actually an empirical result of large scale meta-analyses where people with some hair cell damage are not any more susceptible to further hearing damage than anyone else. Some (erroneously) may fear that their musical career is finished, and this is simply not the case. Well, it may be finished but not for auditory reasons…
- It’s not really the result on the audiogram that we should care about, it’s the other things that go hand in hand with hearing loss such as tinnitus, and pitch perception problems. This helps to remind the musician that they still need to protect their hearing in order to prevent career threatening symptoms such as tinnitus.
- Yes, you have a loss of sensitivity at 4000 Hz (which is near the top note on the piano keyboard), but you don’t have to change the equalization on your recording or change the equalization for their listening pleasure. I am sometimes asked by recording engineers whether they should alter the equalization of their recordings in order to compensate for their audiometric hearing loss. I could go into a description of equal loudness contours (a.k.a. Fletcher-Munson curves) and sometimes do, but I get to remind them that an audiogram is an artificial test where we are only measuring equally loud sounds (i.e., at threshold) which would correspond to the 0 phon curve. An audiogram says nothing about supra-threshold auditory function where speech and music have their energy signatures. The human auditory system plays “catch-up” whenever there is a cochlear hearing loss so nothing needs to be done to offset the loss of sensitivity at 4000 Hz (or any other frequency), in most cases of mild (and perhaps even moderate sensorineural) hearing loss.
So, a visit by a 40-year-old musician means that they get to learn a lot about the role of our brain, hearing protection, prevention of tinnitus and pitch perception problems, and a stroll through the wonderful world of equal loudness contours.