Thursday, October 09, 2008

Human Auditory System: Artificial Cochlea

A next generation implementation of an artificial cochlea has been developed by researchers at the University of Michigan and Tufts University (both in the USA). The natural cochlea is the sea-shell-shaped structure in the human auditory system that is the final stage in the conversion of air pressure variations (a.k.a. sound waves) into neural impulses that convey the frequency and amplitude information information contained in the sound to the brain for interpretation.

EDN (USA technical magazine) has an article which contains more technical detail and pictures on the advance.

I should point out that this version of the artificial cochlea is not an exact replica in form factor (i.e. shape) or function of a natural cochlea. For instance, the artificial cochlea is planar in shape versus sea-shell-shaped; covers the frequency range of 4200 to 35,000 Hz versus the 20 to 20,000 Hz of the human ear; and isn't continually fine tuned by an external processor to focus on frequency bands of interest, like the human cochlea does when one is, for instance, one's brain is picking out a familiar voice in a cocktail party situation. I mention this not to detract from their excellent work, but instead to give you, curious reader, reasonable expectations as to its specifications and performance.


Anonymous said...

there are effect with electromgantic interference?

Keith said...

Dear Anonymous,
I'm not quite sure if you are asking about the artificial cochlea or the human one, which is of course a current and popular topic. As far as the artificial one goes, I can not speak authoritatively on it, but it obviously does have electrodes so it could be susceptible.

As far as electromagnetic "interference" with the human cochlea goes, many people are looking at this subject because of the widespread use of cell (mobile) phones and BlueTooth headsets. In fact, they are looking at more than simply interference with the cochlea but instead with any and all of the body near where the cell phone is held to the ear.

Intelligent people I have spoken to on this subject have widely varying ideas about whether or not cell phones can have an effect. One thing about the variety of scientific opinions that I have noticed is that those that work backwards from trying to figure out what biological structure(s) in the body would be affected by the wavelengths of electromagnetic radiation that a cell phone is designed to radiate seem to generally cluster together while those who look at reports from users cluster together also. I personally would like to see the result of a large scale, long term, blind study before making up my mind. If one's concern is cancer, for instance, a two or three year study is not going to have much to go on as detectable cancers tend to take longer to develop. So, a long term study is about the only way to find out for sure.

Anyway, that is a very long reply to your short questions. I hope that somewhere in here I've answered your question or at least given you some more things to think about.


Anonymous said...

for sure i asking about artificial cochlea. now,i doing research about artificial cochlea. but more to electrical side. that why i want to know whether it effect with cell phone or another electrical device