Determine if VoIP talker is talking or not

Hi there, 

In my app I am using Oculus voIP and getting the pcm samples for playback. That all works fine.

However it seems like I am get the 480 samples regardless of whether the other player is saying anything. Is Oculus always transmitting voice packets even if the player is silent? I am not dealing with a push-to-talk game, so I don't have any players muted. However I thought that Oculus would have some sort of threshold to determine whether sound packets should be sent or not.

Any idea how to detect if a player is speaking? I need this so I can drive the mouth moving animation. I suppose I could analyze the incoming PCM to determine if there are silent spots, but I'd rather not go down that route.

Thanks!