Subject: Re: underwater listening - bone-conduction From: Eckard Blumschein <Eckard.Blumschein@xxxxxxxx> Date: Thu, 6 Apr 2006 17:40:47 +0200Andre Castro <andre_castro83@xxxxxxxx> 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