PulseAudio Volume Control

 PulseAudio Volume Control (pavucontrol) is a simple GTK+ based volume
 control tool (mixer) for the PulseAudio sound server. In contrast to
 classic mixer tools this one allows you to control both the volume of
 hardware devices and of each playback stream separately. It also allows
 you to redirect a playback stream to another output device without
 interrupting playback.