Cochlear Implant Simulations for the Hearing

[Broomstick]

Bumped into and interesting site today, one that attempts to show those of us with normal hearing what hearing is like for someone with a cochlear implant:

Audio Demos for Speech Perception

The simulate the use of different numbers of "channels" (earlier implants used fewer than newer ones) and what speech and music sound like. More or less. People being individuals they can't exactly reproduce how it truly sounds but it does give some idea of what these devices can (and can't) do.

[Chardok]

Those sound terrifying. No wonder many deaf people prefer to not have their implants on unless they have to. Hearing this actually made me sad. I've watched videos of young children's reactions to their iplants being turned on for the first time - some of them are just heartbreaking.

[Alyrium Denryle]

Those sound terrifying. No wonder many deaf people prefer to not have their implants on unless they have to. Hearing this actually made me sad. I've watched videos of young children's reactions to their iplants being turned on for the first time - some of them are just heartbreaking.

Well, even if it sounded better, remember their brains are not accustomed to processing sound, the parts of their brains that were used to processing sound were co-opted for other things.

[spaceviking]

I'm not sure why someone would take the earlier version since it seems to be of little value. In the case of the later versions, while the voices may sound like some sort of demonic monster ocular implants must be a godsend for those who have never heard anything before.

[adam_grif]

In the case of the later versions, while the voices may sound like some sort of demonic monster ocular implants must be a godsend for those who have never heard anything before.

Well if they're installing ocular implants for people with hearing problems, no wonder it doesn't work very well.

[Broomstick]

I'm not sure why someone would take the earlier version since it seems to be of little value.

Maybe because that was all that was available at the time?

[Elheru Aran]

This is part of the reason I haven't plunged for cochlear implants. The greater part, of course, is that when I was a kid (9? 10? somewhere in there) my parents decided to go for it... and turns out it *can't* happen. My ear mechanisms past the drum are basically entirely shot, the cochlea is totally ossified. Chances are I'll never be able to find an artificial replacement for my hearing, as by this point (I became deaf around 1 year old; I'm 26 now) my auditory nerves are probably atrophied completely and the brain centers for hearing have been reassigned entirely. Bit of a shame.

But beyond that, statistics indicate that cochlear implants only really work for a.) older people who become deaf later in life, and b.) young children who are given the implants shortly after they become deaf. People who have been deaf for a long time, and then receive the implant, often wind up rejecting it because it's just too bizarre for them. If by some miracle they figured out how to adapt one for me right now, I'd have to spend the next 3 or 4 years just learning how to hear and talk all over again! I can already speak, I'm just not very comprehensible... but anyway, yeah. That's the deaf person take for you!

[Broomstick]

This is part of the reason I haven't plunged for cochlear implants. The greater part, of course, is that when I was a kid (9? 10? somewhere in there) my parents decided to go for it... and turns out it *can't* happen. My ear mechanisms past the drum are basically entirely shot, the cochlea is totally ossified. Chances are I'll never be able to find an artificial replacement for my hearing, as by this point (I became deaf around 1 year old; I'm 26 now) my auditory nerves are probably atrophied completely and the brain centers for hearing have been reassigned entirely. Bit of a shame.

There are types of artificial hearing that involve bypassing the ear entirely and plugging into the auditory centers of the brain. Naturally, they are more invasive and still experimental. So in that sense you might, one day, be given a perception of sound you don't have now, but...

The brain doesn't let brain go to waste. As you point out, the deaf brain tends to re-assign parts of what would be the auditory regions to other functions (such as language processing and visual interpretation and probably other stuff no one is entirely aware of). Sure, restore hearing to the adult brain that hasn't experienced sound since birth the person will be aware of sound as a sensory input but may by that point lack the ability to interpret the sound and get meaning from it on the most basic level, never mind something as complex as speech. This has, in fact, been demonstrated in adults deaf since infancy who did get cochlear implants. At best you get an expensive surgery than makes no meaningful difference in their lives. They can tell you a sound has occurred, but can't tell you if it's a laugh of joy or a scream of terror, of human or animal or mechanical origin. It's input without meaning.

Cochlear implants and their cousins might reduce the number of people who functionally are deaf but it won't eliminate deafness because not everyone can be helped by them. A cochlear implant doesn't cure deafness any more than a prosthetic leg cures amputation. It's an adaptive aid that, properly utilized, can be a good thing and allow a more normal function but it's not the "real thing" and it's not suitable for everyone.

But beyond that, statistics indicate that cochlear implants only really work for a.) older people who become deaf later in life, and b.) young children who are given the implants shortly after they become deaf. People who have been deaf for a long time, and then receive the implant, often wind up rejecting it because it's just too bizarre for them.

It's pretty damn bizarre for those of us who are hearing now - while I could see utility in a 32 channel implant as, even distorted, it really does provide comprehensible and useful perception of the spoken word (assuming accuracy of the simulation, of course) but it would pretty much kill any desire to hear music ever again, it's just that bad from my viewpoint. It's also a neat demonstration that the human brain is, in a sense, wired to comprehend language, as it's pulling information out of a very degraded signal for that whereas the brain can't interpret non-language input as well via the implant.

As a tool for improving a person's ability to communicate it is a great advance provided the person in question is capable of utilizing it. I recall back when I worked with medical researchers this was a major, major sticking point between medical providers and hearing parents of deaf children. Some parents are objective enough to read the criteria for effective use of the implants, and some are not. If anyone is interested in that aspect of it I'd be happy to expand on my experience, as it involves how appropriateness is determined and also gets into the "why would anyone implant a low number of channels" cochlear implant.

If by some miracle they figured out how to adapt one for me right now, I'd have to spend the next 3 or 4 years just learning how to hear and talk all over again! I can already speak, I'm just not very comprehensible... but anyway, yeah. That's the deaf person take for you!

Eh, you might wind up with better volume control. I've known deaf people with good speaking skills but, being deaf, they can't perceive ambient noise very well and thus don't know when to increase or decrease volume for those of us who are hearing and can't read lips, or who might find the volume offered painfully loud. But, based on studies I've seen on the use of cochlear implants in the real world, while it might help your production of speech by providing feedback you aren't getting right now, given your background it might be that, no matter how much effort you put into it, it would never really help your comprehension of the speech of others because of the brain remapping that occurs with prolonged deafness. The parts of the brain concerned with interpreting language-containing sound have probably been permanently re-assigned to visual work, including reading text, comprehension of sign language if you use that, or lip reading if you use that, and so forth.

[Elheru Aran]

I'm a signer, so yeah. About the only person who can understand my speaking voice consistently-- not 'often', but consistently-- is my wife who I've been with for around 4 and a half years, and that's only with short statements. As such, I believe that even if somehow some device was able to restore some hearing capability to me, I would probably end up more or less in the same boat I am now. What I would receive from the 'hearing aid' would be garbled at the very best, and like I said before, I'd have to spend a long time just getting to the point where I can understand anything, period.

Hearing people have the ability to separate specific sounds out from the ambient auditory environment; for example, you can tell the difference between a person in the same room talking to you, and an actor talking on the television. To a deaf person who's just gotten an cochlear implant... it'd all sound the same... plus, say, a ceiling fan running, the hum of the air-conditioner, cars passing by on the road outside, birds in the trees, dogs barking, and so forth. It's a ugly scene if you think about it, actually. Hearing people have spent a fair portion of their lives learning how to sort this out. Me? Just peeking in the door, haven't even stepped through.

And then after you get the ability to hear, you have to learn how to comprehend sounds, how to distinguish the patterns that make up words... take 'amateur'. Dictionary.com puts the pronunciations as 'am-uh-choor, -cher, -ter, am-uh-tur' (presumably dialectial variations). How do I know that these sounds, put together, form 'amateur'? I don't. I have to go, mentally, "okay, this word goes... uhh... am cher? am uh ter? amateur? is that it?" Then extend that to every word in a spoken sentence, and so on... a bit daunting.

I would almost certainly be able to improve my own speech, though, if only by gaining some control over my volume like you mention. I've had speech therapy at various points, and I have a fair understanding of how to pronounce words in English. Beyond that, though, understanding people would be a whole other matter, leaving alone the whole problem with accents and what not.

Honestly, I see the best solution for myself being this... a speech-recognition program, on some kind of a miniature computer that hangs on my hip, connected to a glasses-projected display, perhaps with a directional microphone of some type on my lapel or something. Face a person speaking to me, microphone picks up their speech, computer converts it into text, projects it on glasses in front of my eyes, does the same for my own speech. Clunky? Probably. Inaccurate? Quite possible. But useful? Yeah. It's not a *hearing* aid, but it would serve a similar function by transmitting auditory information to me in a-- and this is important-- form that I can understand without having to spend long years re-learning how to hear and speak.

[Razaekel]

I will tell you right now, as a cochlear implant user, those are horrible. HORRIBLE. I'm not sure as to the exact number of channels my implant is capable of (I suspect it's a SMSP processor), but I can easily distinguish between the 32-channel sample and the actual sample. Obviously, I'm not capable of the same ability to distinguish fine distinctions between different sound samples as a normal hearing person, but I quite enjoy listening to music of all varieties (except rap), and can generally understand telephone conversations.

These samples are, again, horrible representations of what I'm capable of hearing. Older implants, as in from before 1990, may be limited to those sound qualities, but the newer ones are much better in terms of sound quality. Do not treat these as being representative samples of what a newly implanted person would be capable of hearing.

As an addendum, I may not be a 'standard' recipient. My parents had me using a hearing aid from about age 2 until age 11, at which point I had the cochlear implant installed. As such, I had experience with hearing, and my neural circuitry hadn't atrophied.

[erik_t]

Sampling eight bits from an eight bit source is going to give a different result than sampling eight bits from an analog source. I assume that the people who do this research for a living know how to correct for such effects better than we do.

[Broomstick]

If you go back and look at the page with the demos you'll note that it's based on 1995 technology - over 15 years old. The more recent a cochlear implant the better the performance. So, Razaekel, if you're getting markedly better performance then it could be be because your implant is better than what they were working with, or you were one of the lucky ones and got better than average results, or your brain is particularly adept at signal processing. That is part of it, of course, the more the brain uses a cohclear implant the better use it will make of the information.

Back when the place I was working had a research project on cochlear implants it was lead by a woman who happened to be deaf, but also who would never benefit from such an implant. You see, her ears were perfectly fine, she was deaf due to brain damage, the auditory parts of her brain had been destroyed. Sort of the opposite problem that such implants were developed to deal with. Always thought that to be a bit ironic.