Some existing major hearing aid brands provide external bluetooth mics. I’ve used one such bluetooth mic myself, mainly for one-on-one interaction using an external receiver so I’m not sure how latency compares to low energy bluetooth. The latency is slightly noticeable when I speak through the mic and there’s a mismatch in the time when I say a word and hear it, however it’s not a big deal when someone else speaks to it. I think the benefits from improvements in speech comprehension greatly outweigh any cons due to latency.
I have yet to see a bluetooth solution like the FM system I use. You can have multiple mics - up to 10 connected together. The way it works is one mic acts as a central connection point for the other mics, and it’s the central mic which sends the signal to an FM receiver. The system works by triggering the mic in which the first person talks. It works quite well with minimal latency. I’m not sure which wireless protocol is used to connect the other mics to the central mic. What if, instead of using an FM connection between the central mic and the FM receiver, we could use bluetooth? This way, I wouldn’t need an external receiver with newer hearing aids which have bluetooth built-in.
I’ve also tried induction loops, and while they are beneficial, I’d prefer something more convenient such that I don’t have to wear a wire around my neck. Induction loops also present another problem for me - I found that some movements can throw the angle off and position the receiver such that the signal received from the induction loop is attenuated.
Suppose we take this tabletop mic application and extend it - make it portable. I’d have multiple mics and have each person wear a microphone. To connect this system to a portable induction loop, ideally it would receive the audio wirelessly and then transmit the audio to the hearing aids via magnetic induction. Wouldn’t it be better to transmit the audio directly to the hearing aids without a middleman?
As a result, I think a new solution is worth looking into to accomplish something that was previously only possible with an external receiver - it’s very inconvenient to wear those things everywhere I go.
Given all this, I think having some measurements for how much latency there is when using low energy bluetooth would help in deciding whether this is worth pursuing. A little latency isn’t a dealbreaker. In a restaurant setting, I mute my hearing aid microphones when using external mics in order to alleviate the restaurant noise, thus I don’t hear any echo due to mismatch in latency.
Is it ok to name the brands I’m referring to above? The goal is not to endorse any brands, but for the sake of discussion of what I use. Perhaps it would help you understand what I’m looking for in an open source solution.