nice research by Jay Barlow et al.

[serge masse <>]

 <a  href="http://swfsc.nmfs.noaa.gov/PRD/PROGRAMS/CMMP/accsurv.html"; 
rel="nofollow">http://swfsc.nmfs.noaa.gov/PRD/PROGRAMS/CMMP/accsurv.html</a>
 
 to get to know this work if you do not know it
 already, and hear some recordings.
 
 This was a tip from Mark Fischer -
 <a  href="http://aguasonic.com"; rel="nofollow">http://aguasonic.com</a>
 
 cheers,
 serge masse - <a  href="http://leafy.dev.java.net/"; 
rel="nofollow">http://leafy.dev.java.net/</a>
 canada