[Freeswitch-users] How to pause and resume play an audio file in conference?

How to pause and resume play an audio file in conference? For example: I create a conference room with some members, and play an audio file to them. When someone start-talking, I pause the playing. When nobody talking, I resume play the audio file. BTW, In freeswitch-1.2rc, I tryed play,pause,resume commands, but pause and resume is for recording, not for my needs.