Scotch tape and Music

Marshall Chasin
April 20, 2011

How often does this happen to you?  …. Your “favorite” musician walks into your office and makes an amorphous comment about their hearing aids not sounding right or that they sound downright distorted.  After spending several hundred hours with NOAH and an assortment of other tools, you both throw your hands up in the air and say “I give up!”  There may be an assortment of well chosen words that would go along with this.

Don’t waste your time with soft ware adjustments.  In cases like this the only change will be an increase in your blood pressure.

All digital hearing aids have a major weak point- the analog to digital (A/D) converter.  Modern digital hearing aids are typically 16 bit systems.  A 16 bit system only has a dynamic range of 96 dB (and typically less because of engineering constraints) and even soft music have components that are in excess of 96 dB SPL.  The music is simply over driving the front end of the hearing aids.  Once music is distorted in this way, no amount of software fiddling will improve things.  The trick is to prevent he A/D converter from over driving in the first place.

 

My favorite solution is Scotch tape (but I am sure that any other brand would work as well).  Placing two or three layers of tape over the hearing aid microphone(s) will serve to dumb down the microphone sensitivity thereby fooling the hearing aid into thinking that the input is 10-12 decibels less intense.  I have attached an email I received yesterday from a violinist on the other side of the continent… yes, I receive a lot of emails 🙂

“Dear Marshall:  You are so sexy….” oooops, wrong email…. Let’s try the one below…

“Thank you so much for your instant reply!  I spent a couple of hours today experimenting with the Scotch tape trick.  You’re right, it really works quite well, at least in my living room–not perfect, but a big improvement.  Will try live concert hall soon.  My next move will be to get my hearing aid company to replace the mikes.”

This person was referring to the fact that some hearing aid manufacturers can actually install a less sensitive microphone in the hearing aids.  The software will have to compensate for this by turning up the speech programs by the amount of the microphone attenuation (about 10 dB) but this would be an inexpensive and permanent fix for many hard of hearing people who like to play and/or listen to music.

 

I have attached an audio file demonstrating this.    Hearinghealthmatters

Once there is distortion, nothing will help.  You need to prevent the distortion in the first place.

Next week some neat tricks to modify a hearing aid to handle music.

Leave a Reply