Windows Media Player can read QuickTime. Neither can read RealPlayer files. RealPlayer files are the most compressed but have the least quality. As transmission speeds on the internet increase, audio and video will become better and better for viewing and listening. Here is a short clip of a small jungle cat with audio and video tracks in both .AVI and RealPlayer formats.
Email is just a form of html.
So with the newest versions of the main browsers playable sounds should be able to be used with email. Buddycom presented our first videos on the web back in 1997 when we wrote our famous prediction that streaming video would soon become hip, tres chic, you know commoditized. Our first streaming videos were presented in 1998. Were we correct. It's an idea whose time came a long time ago.