Now you can hear his sounds archived at WildSanctuary.com through a free download from Google Earth. Here's a bit about the California-based nonprofit from its Web site:
Our worldwide collection represents over 3,500 hours of wild soundscapes and nearly 15,000 species. The mission: To help connect people to the wild by preserving, presenting, and protecting the voice of the natural world.
Check it out and show your kids!