Re: underwater listening - bone-conduction

[Eckard Blumschein <Eckard.Blumschein@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

Andre Castro <andre_castro83@xxxxxxxxxxx> wrote:

> I thought I would get a bit more replies

> >>One thing that has been fascinating me is the fact that our  perception of
> >>underwater sound is realized through bone conduction.

> >David Mountain and Darlene Ketten have done a lot of work, especially
> >recently, on hearing and sound conduction in marine mammals - you  might
> >look up some of their recent papers

Cochlea is perhaps not by chance embedded in the hardest bone of the whole body.
Marine mammals are said to hear via fat. So the idea of a vibrating bony
structur of cochlea is not very convincing to me. Of course, audiologists take
advantage of a tuning fork immediately coupling to bone. My question is: What
principle may substitute the function of stapes?

When I tried to understand audiblity of radar, I looked at dynamic pressure
differences between different cerebral fluids, one being linked with scala
tympanii the other one with scala vestibuli. I forgot the details. Brain
includes not just a large ventricel filled with cerebro-spinal fluid CSF but
there is also a protecting layer of CSF between the bony capsula of brain and
its gray matter.

Eckard Blumschein