Cochlear implants

05:04 PM, July 08, 2007

I investigated this because it occurs to me that this is the very best example we have of

how close artificial sense organs come to replicating QUALIA.

I thought abt this in regard to Rima, the ballerina.

this is from Wiki on coch implants:

For people already functional in spoken language who lose their hearing, cochlear implants can be a great help in restoring functional comprehension of speech, especially if they have only lost their hearing for a short time.

British Member of Parliament  Jack Ashley received a cochlear implant in 1994 at age 70 after 25 years of deafness, and reported that he has no trouble speaking to people he knows one on one, even on the telephone, although he might have difficulty with a new voice or with a busy conversation, and still had to rely to some extent on lipreading. He described the  robotic sound of human voices perceived through the cochlear implant as "a croaking  dalek </wiki/Dalek> with  laryngitis </wiki/Laryngitis> ". Even modern cochlear implants have at  most 24 electrodes to replace the  16,000 delicate  hair cells  </wiki/Hair_cell> that are used for normal hearing. However, the sound quality delivered by a cochlear implant is often good enough that many users do not have to rely on speech-reading (  lipreading </wiki/Lipreading> ).  Rush Limbaugh </wiki/Rush_Limbaugh> , U.S. talk radio show host, says that everything sounds normal except that he cannot pick out the melody of new music that he had not heard prior to becoming deaf.

The implant works by using the tonotopic organization of the  basilar membrane </wiki/Basilar_membrane> of the inner  ear </wiki/Ear> . "  Tonotopic </wiki/Tonotopic> organization", also referred to as a "frequency-to-place" mapping, is the way the  ear </wiki/Ear> sorts out different  frequencies </wiki/Frequency> so that our  brain </wiki/Brain> can process that information. In a normal ear,  sound </wiki/Sound> vibrations in the air lead to  resonant </wiki/Resonance> vibrations of the  basilar membrane </wiki/Basilar_membrane> inside the  cochlea </wiki/Cochlea> . High-frequency sounds (i.e. high pitched sounds) do not pass very far along the membrane, but low frequency sounds pass farther in. The movement of  hair cells </wiki/Hair_cell> , located all along the basilar membrane, creates an electrical disturbance that can be picked up by the surrounding  nerve cells </wiki/Nerve_cell> . The brain is able to interpret the nerve activity to determine which area of the basilar membrane is resonating, and therefore what sound frequency is being heard.

Cochlear implants

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