audio problem

yes i was wondering if anyone could help solve a problem im having with my audio in yahoo chat I am gonna paste the pop up im getting when i either try to voice chat or use the calling feature:
The call could not be completed. Your computer's audio equipment (your microphone and speakers) are being used by another program. Please close that program, and then try again.
i dont know what program this could be or how to find out what one it is. PLEASE help me
ty
amy:cry

 

restart your computer and try again.