Audio Switcher is a 100% free, and Open Source application for Windows® Vista, 7, and 8.
Audio Switcher makes switching between sound devices trivial. No longer do you have to go into the Control Panel or the Windows® Sound options, instead there is an easy to access icon, or even hotkeys.
The beautiful part of Audio Switcher is it’s simplicity. It doesn’t try to do too much, it does exactly what is needed; nothing more, nothing less.