Perhaps a strange question...

[FredGarvin]

Has anyone seen any kind of study which looked into the modes of (if such a thing exists) an "average person's" ear drum (timpanic membrane)?

 

[GregLocock]

Haven't seen one, but you'd probably need to ask a medical dude (audiologist) more than an engineer. The timpani is effectively a taut membrane, but the coupling of the litle bones and hence the cochlea to it would add damping. My guess is that the resonance would be above the hearing range of the ear, but there is no particular reason why it would have to be so.



Cheers

Greg Locock

 

[FredGarvin]

Greg,
That is the same assumption I am making. I know resonance happens in the inner ear and cochlea, but I haven't been able to find anything on the eardrum itself. I believe there is no attachment other that the muscular attachment around the perimeter of the drum. So the sound is transmitted to the inner ear thru air. I would think someone has at least modeled it as a thin plate contrained around the entire edge....maybe not...

 

[GregLocock]

I'm sure someone has done it, since the mechanical details of hearing are reasonably well understood. You could try the newsgroup alt.sci.physics.acoustics, which used to have some knowledgeable posters, or else a google search. i think the medical approach may be more succesful than asking engineers. Cheers

Greg Locock

 

[GregLocock]

ha! Art Ludwig had at least part of the answer.

http://www.silcom.com/~aludwig/Physics/Main/Coupling_power.html

First mode is at 4 kHz, hence the maximum sensitivity at 4 kHz, Q is 2.4, power absorption is about 75% of the incident power (ie good coupling) at 5 kHz.

Art's website is always a good place to start.

http://www.silcom.com/~aludwig/index.htm

Cheers

Greg Locock

 

[FredGarvin]

Thanks for the help Greg. Much appreciated.