I stumbled across this article about a blind person who also wears hearing aids.  I can't believe my eyes that there's someone who can put in to words what I experience about the difference between analog and digital.  Digitals make me crazy, and I think this person nailed it: time delay.  The bold type is my own emphasis.  At the article's site, there are posts in the comment section that I thought helpful.

http://deafness.about.com/b/2008/01/30/desperately-seekinganalog-hearing-aids.htm

Desperately Seeking...Analog Hearing Aids

Wednesday January 30, 2008

Apparently, digital hearing aids are not for everyone. I received this e-mail from an About.com visitor. It is long, but the person gives a clear explanation of why digital hearing aids will not meet his needs. After the e-mail is my response, which included a list of companies that still make analog hearing aids:

I am seeking sources for programmable analog hearing aids.


I have a moderate hearing loss, and am also blind. For me, hearing is more than simply a way to communicate, it is a limited form of vision. I navigate among objects in my immediate environment through a process known as echo-location, which involves hearing sounds that i originate, echoing off of objects near by. This is a very subtle process, and digital hearing instruments destroy key information required to perform it.


Since I still have usable hearing left, I am looking for a way to simply supplement my hearing. The open-ear variety of digital aid has been recommended to me.


However, all digital hearing aids I have evaluated so far introduce a certain amount of delay in the signal path, which is a time lapse from the instant a sound impulse is detected at the microphone, until the time it is actually reproduced by the instrument. This finite time delay results in a form of echo, which causes navigational confusion and unwanted sound coloration, especially as it relates to the sound of my own voice.


I am hearing two copies of the sound, one of them direct and immediate through the open ear, and the other delayed by a few milliseconds as it passes through the digital wizardry. From my experience as an electrical engineer, I know that analog amplifiers do not introduce delays of that magnitude.


Really, I simply want to find a nice clean analog aid, but with a few of the nice extras, such as dynamic range compression to deal with recruitment, and a programmable frequency response curve.


Please help! All three audiologists I have visited so far are pushing the digital solution, which just doesn't work for me, and decline to give me any leads on analog devices since *they*, the audiologists in question, don't happen to handle them. Any leads you can offer would be *very* much appreciated.

My response:

I did some research and found these companies still make analog or programmable analog hearing aids:

• Audina
  
• Phonak
  
• Rexton - - their site says they do sell analogs as BTEs.
  
• Rion - their site says they do have very basic aids, which might mean analog.
  
• Unitron
  

Are there any companies that I missed? Fewer and fewer companies are making traditional analog hearing aids but as that e-mail demonstrates, there are still some people who need them.