Homemade Hearing aid

This is a hearing aid, not so small as the others. I built it because my grandmother can't use her smaller ones, she cannot use the mini volume toggle. How does it work? It is designed to amplify sounds for the wearer. Hearing aid are electronic devices that pick up and amplify sounds. By amplifying sound, sounds that the wearer normally would not hear are increased in volume and therefore better communicated. It can help restore many of the sounds that hearing-impaired people are missing. The microphone picks up sounds and sends them to an amplifier that makes them louder. You don't need tonehook or earhook, just a headphone. The volume control, the on/off switch and the battery are inside. This is a replanned hearing aid circuit which works with 2 AA batteries, and has the mono headphone output. I put all of the circuit inside the box (left side of an old headphone). It's very cheap and easy to build it. It's like the ear zoom from the TV, or a spy device. But there is an easier way to make a hearing aid if you have and android phone. There is a microphone, a headset (wired or bluetooth) and an amlifier is in your phone. These are the best choices:

 

And here are some pictures about it:

And Other hearing aid circuit diagrams