audio amp question

I have a client who is looking for the following:

a 9 volt audio amplifier into which a microphone and headphones plug.

The purpose is for him to be able to speak to a man who is extremely hard of
hearing.

Any ideas for a cheap circuit?

Dan

 

I he going to blow up his ears?!
Roman

 

How about a 'personal amplifier'

http://www.seniorshops.com/minitech.html

 

It's a hearing aid for people too vain to buy a hearing aid.

Cheers!
Rich

 

Ok, seriously, I suggest staying away from building a hearing aid.
It's not about one's skill level...it's more about who's going to be
the one blamed if something were to go wrong. It doesn't matter if
your circuit is the cause.

That being said.....

Williams Sound has made some products called "assistive listening
devices"
http://www.williamssound.com/

I'm not sure how willing they would be to part with their schematics,
but there you have it.

Other than that, if you're still interested in making the device...

You can combine a mic pre-amp with a generic op-amp amplifier circuit
for headphones to accomplish the same thing. A good source for
schematics is www.discovercircuits.com

Dan