wgeoff

There is an excellent new book "The Sound Approach to Birding" by Mark Constantine. This is a book about understanding bird sound and comes with two CD's of bird sounds. It explains the modern techniques of sonograms, amongst other things.

For sound recordings, try 'Birds of Tropical Asia 3', a CD-ROM by Jelle Scharringa, Bird Songs International at www.birdsongs.com or there is a CD of local bird sounds by HKBWS.