Mumble

Mumble is an open source, cross platform, low-latency, high quality voice over IP (VoIP) client. Mumble uses a client/server architecture and is primarily used by gamers, but can be used for any VoIP purpose.

Kernel
Many laptops have built-in USB microphones (almost always paired with USB web cameras). The kernel needs the SND_USB_AUDIO symbol enabled to support USB audio (input) devices.

Emerge
Install Mumble:

Unmerge
Uninstall Mumble by issuing: