by Neil Bauman, Ph.D.
A lady asked:
In your article of December 5, 2005, Super-Sensitivity to Sounds you discussed recruitment, from which I suffer severely. I have been unable to find an appropriate hearing aid, although audiologists have said that newer aids might benefit even my profound deafness. Would you tell me the type of hearing aid you use, so that I could try that make and model. I am quite desperate, unable to converse even with my family, and terrified of cochlear implantation-any advice would be welcomed.
When you have a profound loss, recruitment can really be a problem. For some people, as soon as any sound becomes loud enough to hear, it is already too loud to stand. If that is your situation, then hearing aids won’t help you.
However, if you have a bit of dynamic range in which to play (even 20 or 30 dB) then properly fitted hearing aids should be able to help you. (Your dynamic range is the area between the softest sound you can hear and the loudest sound you can stand for any given frequency.)
In order to have hearing aids properly adjusted for you, you need a recent audiogram and you need to have your recruiting levels measured for each frequency and plotted on your audiogram. (In 50 plus years of wearing hearing aids, I think I’ve only had this done once!)
To find your recruiting level at each frequency, your audiologist uses the same pure tones used to find your degree of hearing loss, and continues to raise the volume until all of a sudden your recruitment kicks in and you blink/jump/wince/whatever. They plot these results on your audiogram.
Whoever fits you with a hearing aid then knows that they have to set the compression on each frequency band so that the output of that band never exceeds this figure. In fact, it should be set a bit below this level.
Once you have your recruitment levels plotted on your audiogram, then have your audiologist program your hearing aids to just below the recruiting value for each frequency. You should notice an enormous difference when this is done properly for your specific hearing situation.