Audio Control allows you real-time control over the audio while calling. You may also add audio files as background music.
Click the Select Background Music 
button and an Open window pops for
locating your audio files. (Wav, WMA, MP3)
You may select multiple audio files or drag and drop files for playing. And the audio files play in loop.
Click Play
/ Pause 
button to play or pause the music.
Click Stop 
button to stop playing.
The Volume slider bar allows you to control the volume while you talk.
Click 
to mute all the audio; and
click 
to maximize the audio volume.
The Mixer controls the audio level between music/sound effect and microphone.
Click 
to mute the microphone and
get only music/sound effect.
Click 
to mute music/sound effect
and get only the audio from microphone.