From eyeOS Wiki

Sound Management

Idea

Implement a way for any eyeOS app to play short sound for alert, message, question, etc...
Some common sound should be included with eyeOS for predefined events (ie : calling an error sound from an app).
An app may be able to play its own defined sounds (included in the app's package).

Possible solution : GMail can do this. The way GMail does this is by utilizing a small Flash program, and then the flash applet plays the sound in the user's browser. The flash applet can be invisible, or better yet also allow volume control. -Andrew K. <f00f3d@gmail.com>