Fred Van Gessel, Birds Australia/ Australian Museu: Birds in Backyards is a research, education and conservation program
Birds Australia/RAOU: BA is dedicated to the conservation, study and enjoyment of Australia's native birds and their habitats.
The birdsongs are available online in different formats. In order to listen to them, you will need the appropriate software and browser plug-ins. I recommend Winamp Media Player and the VLC Media Player, both of which can be downloaded for free.