Help to design and build a prototype

I am new here, and not an engineer, so need a lot of help.

Project: To design and build a small inexpensive USB plug-in accessory to capture the audio signal from hearing aid loop systems in auditoriums etc, as audio input to a variety of digital devices, eg. Laptops, iPads etc.

It would contain a miniature telecoil as used in hearing aids, be similar in size to a very small USB memory stick, and powered if necessary from the USB port.

I have lots more I could say about this but this will do to start with. I live in London UK and open to phone contact.

Obviously it has commercial potential, but not much I can do if someone takes up the idea. I have searched the internet and cannot find anything like what I envisage.

Would value any advice and help.
Thanks

I do a lot of prototype it requires you do your own building and testing. I know only a little about what your doing my wifes brother is deaf he has a hearing aid loop systems attached to his TV. I would suggest you find an IC that can be used as a high gain amplifier then build your prototype. You will probably have to build your own hearing aid loop systems in your living room attached to your TV or sterio so you can test it. You won't want to go to a movie theater every time you need to test it. Once you get it working and fine tuned then you can go to a movie theater to see how well it works there.

TTL Cookbook has a lot of ICs you can check out with all the data needed to design your own circuits.

CMOS Cookbook has ICs you might want to check out too.

Go to any electronic sales company and get a cross reference book.

There may be other books if interest too. If your prototype needs to be SMALL I would use ICs because they are small and compact and can be powered by tiny batteries keep away from transistors and large parts.

Thanks for you guidance gary350.

A hearing aid loop preamp uses an opamp, not a TTL or Cmos logic IC.
I have never seen one but I think the signal level depends on the coupling (distance) between the transmitting coil and the receiving coil so an automatic-gain-control circuit might be needed.

If you are trying to build a universal device, the problem is there are at least there different systems in use including IR, RF, and Inductive Loop. Do you plan on detecting all types?