Hearing device

I see advertisements like:
CYBERNETIC EAR!
Enhances Normal Hearing 3 To 4 Times
Use for courtesy lowering of TV volume, etc.. Detect rattles, mechanical abnormalies, leaking gases, air, electrical corona. Excellent safety aid for lab or shop.
Adjustable Volume Control
Fits Into Either Ear
Long Lasting Batteries

and

AMAZING ELECTRONIC TURBO EAR!!
Greatly Amplifies Hearing
High Quality Device
With Hi/Lo Filter
Adjustable Volume
Built In Light Indicator
Uses 1 AAA Battery
Small Size 2.75"x 1.75"x .75"


does anyone have any schematics on how to make a small, high sensitivity hearing aid?

In a nutshell YES! ,
check out the website www.google.com

How about making one like Bush used in the debate so Carl Rove could feed him the lines?

uhoh, politics . . .

Hi DragonMaster,
Most semiconductor manufacturers such as Maxim and TI have "headphones amps" ICs. They might be difficult to obtain though because they aren't a mass-market item. If you aren't handy with a microscope, their very small size might be a challenge to solder.
I've had good results with a normal-size (8-pin DIL) MC34119 bridged amp. Because it's bridged, it doesn't need a big output cap.

The datasheets for the ICs are available with a Google search and have circuits and PCB layouts.

tansis:

In a nutshell YES! ,
check out the website www.google.com

Click to expand...

I already tried that before I got here and I couldn't find anything.

Thanks, audiguru I'll try that