Ed, there is in fact going to be a presentation on this very subject at the upcoming 44th annual meeting of the Herpetological Society of Japan, set to be held in the northern city of Sendai on Nov. 12-13.
If you have any Japanese academician or zoo contacts, perhaps you could contact them and have them record it for you or pick you up a CD, which I guess will be available there for sale to the conference participants. If you don't know anybody who'll be going, perhaps I could ask somebody I know. I'll probably be too busy to go myself, though I did make it to last year's meeting in Kyoto.
The presenters include Ikuo Miura of Hiroshima University's Institute for Amphibian Biology, and (at least it seems) pianist Trevayne Fernandez of the Australian Music Examination Board. Also some people from Hiroshima's Asa Zoological Park and Hiroshima high students who were involved in the DNA decoding project (See:
http://web-japan.org/kidsweb/news/05-03/ssh.html). Contact me directly if you need Miura's e-mail address