Re: AUDITORY Digest - 28 Mar 2006 to 29 Mar 2006 - Special issue (#2006-71) (Bruce Walker )

Subject: Re: AUDITORY Digest - 28 Mar 2006 to 29 Mar 2006 - Special issue (#2006-71)
From:    Bruce Walker  <bruce.walker@xxxxxxxx>
Date:    Wed, 29 Mar 2006 13:49:22 -0500

Andre,

My student, Ray Stanley, and I have been doing a lot of psychophysics  
work on bone conduction (in air, mostly), and we have been working  
with a company that produced bonephones, including some for use under  
water.

Please contact Ray (rms@xxxxxxxx) with more specific queries, and  
he can help where possible. If you have interest in the devices  
themselves, you can let me know and I can put you in touch with the  
manufacturer.

Best regards,

--Bruce Walker
Georgia Tech Sonification Lab




Date:    Wed, 29 Mar 2006 11:20:13 +0000
From:    Andre Castro <andre_castro83@xxxxxxxx>
Subject: underwater listening - bone-conduction

Hello, I=92m sonic arts student at Middlesex University (UK). I=92m  
curre=
ntly I=20
developing a project on underwater soundscapes. My intention is to  
create=
  a=20
body of recordings of underwater sound environments, with which I can  
sta=
rt=20
composing with. Although that has not been an easy job, recording in  
pool=
s,=20
ponds and small rivers, using homemade hydrophones both with piezzo=20
transducers and dynamic mics. However results have been quite  
stimulating=
  to=20
the work.

One thing that has been fascinating me is the fact that our  
perception of=
=20
underwater sound is realized through bone conduction. For what I  
could=20
gather by relating different sources is that when inside water the  
impeda=
nce=20
matching/communication form the ear drum (air) to the inner ear  
(fluid),=20
through the ossicles is stopped. As a result our air conducted  
listening =
is=20
also stopped. We no longer perceive sound through the vibration of  
the=20
eardrum, but through the vibration of the skull and jaw.

I do not know until what point this is as it happens, I am afraid I  
might=
  be=20
speculating quite a bit. However doing quite some research (in  
underwater=
=20
sound, deafness, hearing aids) I haven=92t been able to find almost  
any p=
roper=20
information.



I would be very pleased if anyone could give some insight on this  
subject=
  or=20
point me in some direction (book, website, person) how might help in  
this=
=20
subject.

Cheers,