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Digital technology may offer advantages in its ability to tailor amplification to a particular individual’s loss profile as well as the availability of programm

Digital technology may offer advantages in its ability to tailor amplification to a particular individual’s loss profile as well as the availability of programmed settings for different social situations, plus extra bells and whistles like Bluetooth and app-tracker options. What it cannot do is faithfully reproduce natural sound in a way that is subjectively satisfying and moving and true. Oh buddy do i have a xiph rant for you. I am more or less entirely willing to chalk this up to what I shall politely call “top-down effects”. https://people.xiph.org/~xiphmont/demo/neil-young.html https://people.xiph.org/~xiphmont/demo/neil-young.html Frequency tuning and rapid readjustment of it is the key feature of modern hearing aids and we’re just barely scratching the surface of what we can and should do. Here’s why: presbycusis, or age-related hearing loss, has a cruel fact about it. As the threshold of audibility rises for a particular frequency, the threshold of pain lowers. Rather often, the reason people don’t use hearing aids is that they create a situation in which you can hear but also every sound is painful! Precise digital control of per-frequency intensity amplification can make that a lot less terrible. If it hurts to hear at 4khz, we can squelch that frequency but boost the 100-400hz range and your speech audibility should still get the boost you need to talk to your grandchildren. 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.

TheSoftwareGuy 7y ago
Can you really offload per-packet processing to a connected Bluetooth device without injecting a frustrating amount of latency? Bluetooth isn’t known for being a fast protocol
- sansnomme 7y ago
  How do Bluetooth headphones compensate for the latency?
  - NikolaNovak 7y ago
    I haven't seen them compensate successfully for anything real-time (games). I've seen them compensate for things like movies; I assume they send Audio ahead of time, and "hold" back the video until it's in sync.
  - cjrp 7y ago
    In my experience, they don't; if I'm typing on an iPhone there's a noticeable delay between me tapping a key and hearing the sound in my QC35s.
    - hprotagonist 7y ago
      That's not the bluetooth latency you're hearing, that's just how active noise cancellation works. QC35s buffer about 75ms worth of ambient noise and then phase-invert it and play it back. This destructively interferes with the outside noise, and cancels it. But you have to sample your environment on some time window to get it to work, so when ANC is on, there's lag. This is also why ANC only works well for slowly-varying noise like airplane drone, but can't handle impulsive sounds like gunshots. https://en.wikipedia.org/wiki/Active_noise_control https://en.wikipedia.org/wiki/Active_noise_control
      - cjrp 7y ago
        Interesting, thank you!
  - nickthegreek 7y ago
    Apple uses a special chip, the W1 or H1 to resolve syncing issues. But that wouldn't work well for these situations as they cant control the visual syncing of a live person.
  - iwalton3 7y ago
    There are also lower latency bluetooth codecs. I use LDAC with my headphones on my computer, and I don't usually notice any latency.
    - opencl 7y ago
      How are you using LDAC with a computer? Windows and macOS don't support it, there's some fork of pulseaudio that has it for Linux but I never figured out how to get that working.
- hprotagonist 7y ago
  I know it’s being tried. Good question, though. I can’t imagine it’s super easy, and maybe some other protocols are in the mix. The obvious stopgap measure is the neck-torc approach. Offload computation to a bespoke thing and use an app for tuning, or the like.
- deleted 7y ago
  [deleted]
- analog31 7y ago
  I'd be concerned about battery life. Those tiny batteries are expensive, and changing them is a challenge, especially if you have the vision and dexterity problems associated with age.
dreamcompiler 7y ago
I love that Xiph rant and have it bookmarked. > 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.
- repsilat 7y ago
  > 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. https://www.wolframalpha.com/input/?i=speed+of+sound+*+10+milliseconds https://www.wolframalpha.com/input/?i=speed+of+sound+*+10+mi...
abtinf 7y ago
Would it be possible to shift/autotune the painful range to a different range, to preserve input while reducing pain?
markandrewj 7y ago
Just to expand on your comment, I don't think there is an analog hearing aid that has a working solution for the "cocktail party effect". There are several advantages to digital hearing aids. https://en.m.wikipedia.org/wiki/Cocktail_party_effect https://en.m.wikipedia.org/wiki/Cocktail_party_effect

TheSoftwareGuy 7y ago

Can you really offload per-packet processing to a connected Bluetooth device without injecting a frustrating amount of latency? Bluetooth isn’t known for being a fast protocol

sansnomme 7y ago
How do Bluetooth headphones compensate for the latency?
- NikolaNovak 7y ago
  I haven't seen them compensate successfully for anything real-time (games). I've seen them compensate for things like movies; I assume they send Audio ahead of time, and "hold" back the video until it's in sync.
- cjrp 7y ago
  In my experience, they don't; if I'm typing on an iPhone there's a noticeable delay between me tapping a key and hearing the sound in my QC35s.
  - hprotagonist 7y ago
    That's not the bluetooth latency you're hearing, that's just how active noise cancellation works. QC35s buffer about 75ms worth of ambient noise and then phase-invert it and play it back. This destructively interferes with the outside noise, and cancels it. But you have to sample your environment on some time window to get it to work, so when ANC is on, there's lag. This is also why ANC only works well for slowly-varying noise like airplane drone, but can't handle impulsive sounds like gunshots. https://en.wikipedia.org/wiki/Active_noise_control https://en.wikipedia.org/wiki/Active_noise_control
    - cjrp 7y ago
      Interesting, thank you!
- nickthegreek 7y ago
  Apple uses a special chip, the W1 or H1 to resolve syncing issues. But that wouldn't work well for these situations as they cant control the visual syncing of a live person.
- iwalton3 7y ago
  There are also lower latency bluetooth codecs. I use LDAC with my headphones on my computer, and I don't usually notice any latency.
  - opencl 7y ago
    How are you using LDAC with a computer? Windows and macOS don't support it, there's some fork of pulseaudio that has it for Linux but I never figured out how to get that working.
hprotagonist 7y ago
I know it’s being tried. Good question, though. I can’t imagine it’s super easy, and maybe some other protocols are in the mix. The obvious stopgap measure is the neck-torc approach. Offload computation to a bespoke thing and use an app for tuning, or the like.
deleted 7y ago
[deleted]
analog31 7y ago
I'd be concerned about battery life. Those tiny batteries are expensive, and changing them is a challenge, especially if you have the vision and dexterity problems associated with age.

dreamcompiler 7y ago

I love that Xiph rant and have it bookmarked. > 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.

repsilat 7y ago
> 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. https://www.wolframalpha.com/input/?i=speed+of+sound+*+10+milliseconds https://www.wolframalpha.com/input/?i=speed+of+sound+*+10+mi...

abtinf 7y ago

Would it be possible to shift/autotune the painful range to a different range, to preserve input while reducing pain?

markandrewj 7y ago

Just to expand on your comment, I don't think there is an analog hearing aid that has a working solution for the "cocktail party effect". There are several advantages to digital hearing aids. https://en.m.wikipedia.org/wiki/Cocktail_party_effect https://en.m.wikipedia.org/wiki/Cocktail_party_effect