[blindkid] Aftershokz Bone Conduction Headphones

Tue Sep 25 12:58:16 UTC 2012

I don't think there is an absolute answer as it would depend somewhat on the details of your hearing loss, but I suspect these may possibly work for you. 

If you read the links I posted or search on Google, you can find more about Beethoven and his apparent initial approach. It seems the concept was helpful for him. Biting the rod, in his case, sent vibrations into his jaw bone-- well, technically, through his teeth and so forth (and I presume directly into his skull, though they seem generally to focus on the jaw) so sound went directly from the piano into his bones, and that got to parts of the listening center which still functioned. This design of headphone seems to take a similar, if slightly more convenient approach. I found a vintage video on YouTube of the Bone Phone. It fired small speakers towards your neck, near the collarbone. People near you could hear them, but it was much quieter for them than for the wearer. Others here may have more details on the piece DrV found, but most likely they will be much quieter for those nearby than the older system. I do read they can still be heard in a quiet room by others.

Bone Fones were well liked, but Walkman type radios appeared soon after the release of the Bone Fone and were smaller, cheaper, lighter. At $70 (in 1980) Bone Fones sales sharply dropped when $50 or less Could get you a  (now) conventional personal stereo. 

I always feel at a loss trying to describe or grasp from a description how much a blind person can or cannot see. Likewise with hearing loss.

As I understand it, you're bypassing PART of the natural auditory path, so if your loss (or at least some part of it) is located in the areas you're bypassing, it should be helpful. If not, I would expect no change. You can experiment with the concept somewhat by listening from outside a room where there is a lot of sound and see what you can pickup though a sound transmitter like a glass window or a steel door frame. Wood or drywall dont work as well. Also try a speaker cabinet when you go into contact with it with your jaw or forehead (use the top, side, or back..., or something like a steel rod might let you transfer the sound more precisely. You must have firm direct physical contact.

Even the old eaves dropping glass trick, where you put a glass against a door or window and your ear against the glass might make a slight demo-- you'd need to be in firm physical contact with the glass, and again, it would probably work best to get the vibrations more directly into your jaw or forehead. The soft tissue of your ear shouldn't transfer the sound as effectively for the bone conduction effect.

An easy way to demo the concept through your forehead is to rest your forehead against a running motor, through  a refrigerator or a washing machine.

Anyone aware of the way sound behaves underwater has a bit of an idea of how this works, and if you've ever heard a loud pop of your joints when submerged in a pool, like your fingers cracking? The sound is coming largely through your bones in that case, as I understand it. Try it yourself and then have a friend pop fingers. Note the difference. Water will transfer their sound pretty well too. Far batter than just the air...

Now for those with typical hearing who think I'm nuts, there's one more little detail. When you are hearing sound that competes with these effects through the air, you probably won't notice. Put on some attenuators or use some ear plugs, or simpler still? Plug both ears with your fingers (carefully) and walk across the room. Even on carpet, you'll probably hear a "thunk" with each step. Why? That is the vibrations of your footsteps going from the floor up to your ears through your bones. Compare with shoes on and off. Shoes dampen the vibrations and the sound is quieter. Try hard soled shoes on concrete or tile... Lots of variation. I am especially struck by the effect of attenuators when weed trimming. Trimmer gets much quieter while footsteps get effectively amplified. It feels really strange to me.

In a quiet room, an ultra sensitive mic will pick up a similar sound, by the way, but it must be a FULL RANGE mic.

Sent from my iPad

On Sep 25, 2012, at 7:43 AM, Gerardo Corripio <gera1027 at gmail.com> wrote:

> Ok. And for us hearing aid users, will these work the same way since hear not through the ear, but through the hearing itself?
> 
> Enviado desde mi iPhone
> 
> El 24/09/2012, a las 23:19, Richard Holloway <rholloway at gopbc.org> escribió:
> 
>> Very interesting. I'm not certain "new technology" is totally accurate, but I haven't seen any fresh bone conduction products for a long time. Several sources claim the concept was discovered at least as early as Ludwig van Beethoven, who was nearly deaf. It is claimed that he would play a piano attached to a rod and then he could bite the rod and actually hear through his jawbone.
>> 
>> Back around 1979 there was a product called the "Bone Fone". As I recall they only offered it as a personal radio but there may have been a "headphones only" version (I only ever saw a radio version). It was a slightly different concept in that you wore it around your neck over your shoulders, almost like a towel draped around behind your neck and down over your collar bone, but it had to be the same basic system. Bone Fones sounded pretty good "back in the day". As I recall (and as would make sense technically) there was reduced sound frequency response on the high end-- don't expect crisp, "sizzling" highs with music.
>> 
>> I expect I will want to try a pair of these myself. Wish I could test them locally, but I haven't ever seen any around locally. I think Kendra would like them and I could see myself using a set at the gym as well. For those not familiar with the concept, since the sound doesn't go through the air conventionally, they are nearly silent for those nearby the headphones, and this also means the sound is not going straight into the ears, so sound in the room still sounds normal. A student should be able to use the headphones and still hear a teacher or the student in the next desk talking, for example.
>> 
>> If you have ever put your chin on something like a speaker cabinet that suddenly made music get louder in your head, or I can recall doing the same thing with my forehead before, I guess it was probably against a glass window with loud music on the other side, that is the effect I would anticipate.
>> 
>> I think the Jawbone bluetooth headsets actually use the reverse principle to pickup your voice for the mic m