> Throw a BLE connection to a nice multicore GPU smartphone into the mix and we can start offloading really complicated processing to the thing in your pocket.
In principle yes, but latency is the nasty problem in this scenario. The wearer is still hearing some ambient sound in addition to processed sound, and if processing latency is greater than about 10 ms (IIRC) it drives the listener nuts and they won't wear the aid. The problem with smartphones is they have too many layers of general-purpose OS cruft sitting on top of the
A/D and D/A. I've read that IOS is better than Android in this regard, but for lowest latency you really need a dedicated realtime processor and a realtime OS.
> if processing latency is greater than about 10 ms (IIRC) it drives the listener nuts and they won't wear the aid
For context, sound travels about 3.4 metres (11 feet) in 10 milliseconds. Of course, this is added to the time taken for the sound to reach the microphone.
Our brains apparently correct for this sort of lag without us noticing, but maybe (I have no idea) this correction is calibrated to perceived distance.
> Throw a BLE connection to a nice multicore GPU smartphone into the mix and we can start offloading really complicated processing to the thing in your pocket.
In principle yes, but latency is the nasty problem in this scenario. The wearer is still hearing some ambient sound in addition to processed sound, and if processing latency is greater than about 10 ms (IIRC) it drives the listener nuts and they won't wear the aid. The problem with smartphones is they have too many layers of general-purpose OS cruft sitting on top of the A/D and D/A. I've read that IOS is better than Android in this regard, but for lowest latency you really need a dedicated realtime processor and a realtime OS.