I'm not a hearing aid expert but the microphone and earpiece may currently be tightly coupled because it has to be. That is, human ears are very sensitive to phase shifts and time delays. Placing the microphone in a location that is not your ear may throw off your hearing somewhat (possibly ability to locate from where a sound originated).
I can vouch for this. I used to have an FM system - this is a mic that transmits on a very specific FM frequency
to a receiver that's paired with my hearing aids. I loved it because I could easily use it to hear people near me in loud rooms, but it sucked in meeting rooms. The reason why is that I would hear someone speaking through my hearing aids and through the mic - at slightly different times. This is the phase shift Dwolb speaks of. This reduced clarity significantly.
That said, if analog31 wants to wear the mic on his shirt, that distance is actually good enough for most 1 to 1 conversations. Just understand that you're trading off "spatial perception" (no left/right balance if only one mic).
Short after losing one of my ears audition I was laying on a beach at the Mediterranean. Holydays, sun, good times. Then I felt a strong buzzing sound, it had to be a gigantic flying insect, so close to my head!. I jumped out of the towel and run some meters flapping arms around my head. Crowded beach and my own wife were perplexed at me and my flapping arms strategy did nothing for the sound that was still as loud an close.
Then my brain recalculated. Sound stopped and started again and the pattern was obvious then. I confused for some good 5-7 seconds a halfmile away boat siren with an insect around my head.
By first hand experience: It's amazing what the brain does triangulating the two ears input, and it is indeed very sensible to the quality of the inputs. On the other hand the brain is also great at adapting to new, lower quality sensors. I don't see that same scene happening now, after several years of one sided hearing.
My wife still recreates that moment from time to time.
Many modern hearing aids already have ways to do what he's looking for.
Bluetooth receivers for television or phones, for example. In other cases, I've seen lapel microphones meant to be worn by the person speaking.
If analog wants to build their own for the sake of the experience, or for cost, then I'm certainly not going to discourage them. But if all they want is the solution to that particular problem, it already exists and is being sold.
As a hearing aid user: my spatial awareness (as provided by sound information) is pretty much borked anyway. If I can't see where a sound is coming from I have no way of knowing what direction it's from or how far off it is. Even a small amount of hearing loss can cause this problem.
Another advantage of having the microphones (yes, there can be more than one!) near the ear itself is for DSP. Many hearing aids use multiple microphones to selectively amplify sounds from the direction you are facing. I think this would work best with microphones near the ear, or at least in a known position.
definitely. binaural hearing is very important. a single microphone in your shirt pocket would be a bad idea and not even close to the quality of hearing you can get with current hearing aids.
