Cochlear fluid

[goldglow]

I am puzzled as to how the cochlea can simultaneously differentiate between sounds of different frequencies and pressures. For example, if i sit listening to a string quartet, with all the instruments equidistant from me, ( some playing louder than others ), my eardrums react to the strings vibrations and deliver them, ultimately, to the cochlea, which transforms these vibrations in air into vibrations in fluid. How, then, can the same, single fluid cope with so many different wavelengths of sound and pressure at the same time?

 

P.S. Could i ask the same question about the eardrums too?

[Strange]

P.S. Could i ask the same question about the eardrums too?

 

 

And the atmosphere in between the instruments and the ear, presumably.

 

The cochlea contains a series of hairs which act as tuned detectors, each sensitive to a different frequency [range]. The brain analyses all those to put together the sounds we hear.

[goldglow]

Great answer. Thanks.

[Velocity_Boy]

I am puzzled as to how the cochlea can simultaneously differentiate between sounds of different frequencies and pressures. For example, if i sit listening to a string quartet, with all the instruments equidistant from me, ( some playing louder than others ), my eardrums react to the strings vibrations and deliver them, ultimately, to the cochlea, which transforms these vibrations in air into vibrations in fluid. How, then, can the same, single fluid cope with so many different wavelengths of sound and pressure at the same time?

 

P.S. Could i ask the same question about the eardrums too?

 

 

You may!

 

What's up, Goldie?

 

So.....the eardrum is the term we use for the "tympanic membrane" of the ear. It is a tightly-drawn (like the skin of its titular musical instrument, the timpani!) membrane that vibrates in response to various waves of air pressure that are exerted upon it when a sound is emitted. This is the beginning of the sound detection process you're asking about.

 

Then the cochlear fluid is stimulated by those vibrations. Think, tapping on the outside of a glass filled with water and how the water would molecularly vibrate. These vibrations (mini waves?) then stimulate super fine hairs that are in turn vibrated. Stimulates. Think tiny antennae on an insect wiggling about as you have probably seen. These vibrating hairs are then converted into electrical signals that are sent to the brain and processed by your auditory cortex in the temporal lobe, which is the part of the brain that processes auditory stimulus. Just as the occipital lobe is the portion of the brain responsible for discerning and processing visual stimuli.

 

Check out this animated video that puts in pictures how this process works. Feel free to ask any more questions you may have on this topic. I'm currently doing some auditory clinical testing and research with a colleague who is an Acoustics doc student.

 

VB

 

[goldglow]

Fascinating! Thanks,VB, much appreciated. This next question may seem silly,but how do we hear internal body noises like a tummy rumbling or humming to oneself, when, I assume,there is no atmospheric disturbance to stimulate the eardrums?

Edited April 27, 2017 by goldglow

[StringJunky]

Fascinating! Thanks,VB, much appreciated. This next question may seem silly,but how do we hear internal body noises like a tummy rumbling or humming to oneself, when, I assume,there is no atmospheric disturbance to stimulate the eardrums?

Conduction of vibrations through the body which reach the cochlear and vibrate the fluid

[rangerx]

Fascinating! Thanks,VB, much appreciated. This next question may seem silly,but how do we hear internal body noises like a tummy rumbling or humming to oneself, when, I assume,there is no atmospheric disturbance to stimulate the eardrums?

We hear ourselves better than we might think. Vibration of the skull, sinuses etc. aid us to modulate our voices accordingly. This is why our own voices sound foreign to us while listening to recordings.

 

A deaf person can speak, but has difficulty modulating hence their voices sound somewhat juvenile.

[StringJunky]

A deaf person can speak, but has difficulty modulating hence their voices sound somewhat juvenile.

Some deaf people can sound juvenile.

 

Evelyn Glennie is totally deaf and a fantastic percussionist... she's nothing short of awesome. Does she sound juvenile?

 

https://www.ted.com/talks/evelyn_glennie_shows_how_to_listen

[goldglow]

Conduction of vibrations through the body which reach the cochlear and vibrate the fluid

Thanks, SJ; that sounds right ( no pun intended! ), and, yes, Evelyn Glennie is an amazing musician: i once saw her perform a long medley of different types of music at different tempos, on several separate percussion instruments, moving from one to the other in quick succession, backed by a full orchestra , without missing a single beat- and it was the orchestra that changed tempo as she moved between instruments.

Edited April 27, 2017 by goldglow

[StringJunky]

Thanks, SJ; that sounds right ( no pun intended! ), and, yes, Evelyn Glennie is an amazing musician: i once saw her perform a long medley of different types of music at different tempos, on several separate percussion instruments, moving from one to the other in quick succession, backed by a full orchestra , without missing a single beat.

Cool. Come to think of it that's how Evelyn 'hears'; vibrations on/through her body and face, as well as an intimate understanding of musical scores and timing.

[goldglow]

Yes. Amazing.

[rangerx]

Some deaf people can sound juvenile.

 

Evelyn Glennie is totally deaf and a fantastic percussionist... she's nothing short of awesome. Does she sound juvenile?

 

https://www.ted.com/talks/evelyn_glennie_shows_how_to_listen

Certainly not. She's very talented and inspiring. I was speaking generally. While not a singer, her voice is quite clear with a gaelic accent. She was not born deaf, but became deaf as a young teen.

 

She's obviously gone to extraordinary lengths to condition herself to listen to sounds in the absence of cochlear function. Any deaf person could, whether they choose to or not may vary widely.

 

Many deaf people speak only as well as they are taught or willing to develop, hence there's a juvenile overtone in some as you've suggested. I didn't mean to be insensitive (sorry). For example, actress Marlee Matlin, who is quite articulate, but juvenile in diction. It's likely because she doesn't care insomuch as how she sounds insomuch as being understood. In Children of a Lesser God, her role was to convey the conflict and pressures of being a deaf speaker in a hearing world, in the absence of hearing folks understanding her silent world. As such, doesn't feel the need to speak perfectly.

 

I was a DJ in a club many years ago and was quite moved when a deaf girl came to the booth, using sign language to request I play Billy Jean by Michael Jackson (her friend translated). When the track started playing, I was looking for her reaction. I could see her eye's roll a little as she looked blindly into space, getting a feeling for the sound. Then she darted to the floor and started to dance.

[StringJunky]

Certainly not. She's very talented and inspiring. I was speaking generally. While not a singer, her voice is quite clear with a gaelic accent. She was not born deaf, but became deaf as a young teen.

 

She's obviously gone to extraordinary lengths to condition herself to listen to sounds in the absence of cochlear function. Any deaf person could, whether they choose to or not may vary widely.

 

Many deaf people speak only as well as they are taught or willing to develop, hence there's a juvenile overtone in some as you've suggested. I didn't mean to be insensitive (sorry). For example, actress Marlee Matlin, who is quite articulate, but juvenile in diction. It's likely because she doesn't care insomuch as how she sounds insomuch as being understood. In Children of a Lesser God, her role was to convey the conflict and pressures of being a deaf speaker in a hearing world, in the absence of hearing folks understanding her silent world. As such, doesn't feel the need to speak perfectly.

 

I was a DJ in a club many years ago and was quite moved when a deaf girl came to the booth, using sign language to request I play Billy Jean by Michael Jackson (her friend translated). When the track started playing, I was looking for her reaction. I could see her eye's roll a little as she looked blindly into space, getting a feeling for the sound. Then she darted to the floor and started to dance.

I'm deaf myself up to about 75dB, depending on frequency but it's pretty evenly knackered across the range I can hear, so I'm perhaps rather acute to over-generalisations about deaf people. WRT music, it matters not that one can't hear everything in it but that what you can hear/feel physically is meaningful.

Edited April 27, 2017 by StringJunky

[goldglow]

Just to go off on a slight tangent,a 13th century European monarch,Frederick the Second ( a fascinating character ) had a passion for languages ( he spoke 6 ) and wanted to discover what was the first language ever spoken - the " natural language of Adam and Eve " - so he isolated several new-born babies and forbade anyone to ever speak to them. ( This was one of his less bizarre experiments! ). Needless to say, the poor children never spoke any language apart from baby noises. I personally don't know anyone who has congenital deafness, but I imagine they must find themselves in a similar situation to those children in their formative years. In my heart of hearts,I truly hope that no one finds this crass or insensitive, but if anyone following this thread has this degree of hearing-impairment, I would be really interested to know if a lack of a learned language in infancy had an affect on their early thinking-processes. For myself,I can't think of anything without thinking of the word first.