Here's where we are on hearing aid selection. We have 2 tiers from each of 2 manufacturers (Phonak and for a total of 6 hearing aids under review.

A look at the links, which go to the best notes for each type of hearing aid I was able to find, will probably leave engineering-inclined people somewhat... lacking, which is right about where I am right now. What the heck is "Music Widening" or "Life Learning" (Oticon Agil) and why would I want it? Technical specifications, please? Somewhere?
Even the best "datasheet" I found (Oticon Chili) wasn't much of a datasheet, though it was interesting to see the hearing aid's frequency response in an ear simulator, and to learn that its total harmonic distortion is 2.5% at 500Hz. Great, but how does that compare to other hearing aids and to human perception thresholds? When I need sounds amped up to jet-engine volume, will 82dB of peak gain do me much good? (I am pretty impressed by the power draw of 1.2mA on average.)
I asked Dr. Krishnan where to find better specs, and she said that was basically the same information that audiologists got too; hearing aid researchers like Dr. Alexander would know more, but that's because they test the aids themselves in their labs and get their own data, not because the company provides them with any more. Okay. So I asked a lot of other questions, and learned useful things:
  • These should all be equally durable.  They'll last me 5-7 years and are equally rugged against damage due to running in a rainstorm, dropping on the floor, and other likely-to-be-done-by-Mel things.
  • The approximate frequency and helpfulness of available software updates are equal across all six aids. (And I am reminded, once again, how many people want to think of their technologies as Magic that Works... which is fair, because that's how I want to treat a lot of things in my life too. Like, for instance, the toilet.)
  • Programmability and hackability are equal across all six aids, which is to say "none of them are hackable at all." Sadface. Even audiologists don't really get to play around with these things. I'm... I'm digging deeper.
And there are a few more things I'm poking at. For instance, all these hearing aids come with a Bluetooth connectivity option that allows the aids to get Bluetooth audio input. But can they do output? I doubt it, but if the answer is yes, then... all sorts of cool stuff opens up. For instance, if I'm conducting an interview for research, I could hook my hearing aids to my bluetooth-enabled laptop so it records the sounds I'm listening to without the need for an external recorder. Or if I'm walking through a busy market with street musicians every few yards, I could call someone on the phone and let them listen to the world through my ears and hear the things that are surrounding me in 3D. (I think most people would use this feature for phone calls without the need to buy an additional hands-free kit. I suppose I could do that too.)
Going further along those lines... I'm thinking about all the fun configurations I could experiment with given different kinds of connectivity; for instance, these hearing aids come with an optional microphone accessory I can clip to the lapel of a speaker I'm listening to, but they all have a limited range. Smash the limited range! Give the speaker a bluetooth microphone paired with a bluetooth-enabled cell phone, then having that call go to my bluetooth-enabled cell phone and from there to my hearing aids, and bam, "infinite range" speaker mic.
The catch: the hearing aids themselves don't actually have bluetooth. They have some sort of short-range wireless signalling (I don't know what kind, I don't have datsheets/specs to find out) that goes to a neck pendant the size of a deck of cards that is the bluetooth transmitter. And yes, the range is such that I have to wear it around my neck; I supposedly can't clip it to my belt/pocket because that's too far. (Yes, I'll be testing this.)
This is a random braindump that's way less organized than I'd like because I'm in the hectic middle of finishing three papers right now -- one conference/research paper, two class thesis papers. But hey, release early release often; get these notes and thoughts out there so other people can tug at them. What specs should I be asking about, where can I find them, how can I tinker better with this stuff?