Help with invention, but might be impossible.?

Not a bad idea. There is enough room in a variety of spots in your body to surgecally implant it and the technology is advanced enough to develop one right now. It could be reloaded from a wireless interface. You would probably have to apply pressure for the controls and then the only difficulty would be how yor connect the audio, i.e. through connection to the auditory nerves or with a transducer. It would be patentable at this stage with some effort. Think about the size of a pacemaker.