On November 2, 2011 I was involved in a serious auto accident. The car I was driving smashed almost head-on into another car. The impact was violent enough to deploy the air bags in my car. Because the windows were closed the sudden momentary increase in air pressure was enough to affect my hearing.
A few days later I discovered the extent of my hearing loss. It affected audible frequencies above 900 HZ (cycles per second). My perception of musical notes above that frequency was shifted upward by about the fourth root of 2, or approximately nineteen percent in frequency. In musical notation that amounts to an increase in pitch by a minor third. The following diagram illustrates in musical notation the difference between
the notes as actually created on a musical instrument such as an organ or piano and my perception of these individual notes. As you can see, between A' (880 HZ) and the next higher note there is a jump in my perception or "hearing" of the notes.
The way I discovered this effect was in trying to play a recorder. The instrument was an "alto" and has a range from F above middle C to F'' two octaves higher. When I tried to play the note C'', two octaves above middle C, it sounded like E-flat about a step and a half higher. At first I thought I was fingering the note incorrectly. I tried other fingering but could not manage to produce a note that sounded to me like C''. I then tested my hearing with the piano and found the same effect. The note C'' on the piano sounded like E''-flat, and so on. Interestingly, all the notes above this strange gap in my hearing perception were consistent with each other. It's as though I have two different hearing scales, one for notes above 900 HZ and one for notes below 900 HZ. I'm rather severely deaf in the other (left) ear but I was able to test it with a computer and ear phones. In that ear the transition from one scale to the other occurs at a lower frequency - about 600 HZ.
I write this blog to present this hearing problem to anyone who may be interested. I have not found a description of this particular hearing problem in a quick search using Google. It may be described some place. If so, and if there is anyone who has investigated this problem, I would like to learn about it. Please write.
Labels: air bag related hearing loss