From Silence to Sound

https://medium.com/@cmmhartmann/from-silence-to-sound-a93f742fae88

by esoteriq • 8 years ago

33 7 8 years ago

Author’s Note. Although I use the word “hear” to refer to how I perceive sound, that’s not an accurate term. Since cochlear implants bypass the natural hearing process, we can’t properly call it hearing.

This is partially true. CIs replace everything up to the auditory nerve -- the hair cells in the cochlea, the mechanotransduction at the eardrum, etc are all literally short-circuited by the implant.

However, much of what we call "hearing", and basically all of the perceptual aspects of it, begin on the AN itself, or in the areas of the brainstem and midbrain that the AN projects to. These areas receive input from the AN as would be true in a normal-hearing individual, with the caveat that the available frequency spectrum is greatly reduced.

jrace• 8 years ago

As someone who spent over a decade working with heard of hearinga nd hearing amplification devices, I would argue that (much in line with your statement) we don't "hear" anything until the auditory center in the brain process the sound.

Even those with normal hearing do not process all sounds that arrive at out Tympanic Membranes (and if we did...we would likely go insane from over stimulation).

I had quite a few patitents that lost most of there hearing yet still had constant tinnitus.

A small few even reported the tinnitus changing from a constant tone (whne they had mild hearing loss) to almost recognizable speech and/ or music once they had severe hearing loss.

It could be argued that even though they had next to no hearing they still "heard" more than they cared for.

woliveirajr• 8 years ago

This silence is the most absolute that any human can experience, one beyond the best noise-canceling headphones or earplugs.

The author mentions how she likes silence. This is interesting, as non-100%-deaf people began to hear noises even before being born, and even when placed in the best anechoic chamber will still hear sounds from the own body. So few people in the world really knows what silence is.

kradeelav2• 8 years ago

I was one of the few who was also implanted in '91, at 2 years old. (My parents had to wait as medical regulations wouldn't allow the surgery to be done to younger kids - nowadays they do at ~6 months, iirc. As the article briefly mentions, the younger you are, the more neural plasticity you have.)

It's interesting to read the difference in experiences as for all intents and purposes I was raised as a hearing-only child (no sign language or lip reading) and didn't quite grasp the nuances until much later on. There was ~7 years of speech therapy to close the gap (so to speak) to hearing kids, but after that it's been repeatedly mentioned that most folks assume that I hear like everyone does. Wouldn't have it any other way, honestly - having that modification done opened so many doors. (That being said, like the author, it's amazing to be able to take the CI off to go to sleep. Soundless sleep is something to be enjoyed.)

Would be happy to do an impromptu AMA if anyone has pertinent questions on the topic. (Keep in mind that singular experiences are only singular experiences.)

mojuba• 8 years ago

I'm very curious about the resolution and quality of the implant and how does it affect how you hear music. Can you distinguish half tones? Can you hear differences between similar sounding but different instruments (i.e. think of various types of the flute)?

kradeelav2• 8 years ago

Those are good questions! Resolution is definitely less when it comes to music - I can hear obvious signal degradation when it comes to somebody talking through a bad phone reception for example, but the difference between a high-def mp3 and a low-def mp3 is near indistinguishable.

I don't -recall- hearing half tones but that may be because I avoided classical music out of personal taste and after a childhood of mandatory piano lessons... it's been a while since I've gone near an instrument. Amusingly picked up a strong fondness for 80's synthpop/EDM/industrial which feels like it could be partially explained by it being 'beat heavy' and less delicate/subtle with different instruments. Would be a fun study!

edit: Jumping back to explain that resolution/quality vastly varies from person to person, even if they're using the same generation of devices - to make a long story short, CI's hook up to electrodes within the ear, and the more electrodes that can be sync'd, the better the resolution. Mine was an odd case where I have a facial nerve right next to a cluster, and those had to be turned off otherwise it would cause my face to twitch excessively whenever a certain pitch of noise was played.

There's also single-implant users and bi-lateral implant users - most folks these days opt for bi-lateral as you do get a whole 'nother level of quality; I was one of the early bunch and have other medical complications that make another surgery very difficult, and decided that since the single's been fine for daily use, it's worth it just to stick with it.

spacejunke• 8 years ago

I cried reading this. Thanks for sharing your story.

From Silence to Sound

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