Plantronics USB Headset No audio

I'm using a plantronics .audio 85 headset. I've set the input to be the plantronics headset. This shows up in the sound preference pane. I have the sound output routed to the headset also. If I play a song in itunes I can here on the headset. I get no response from the microphone. I know the headset microphone works I connected it to my italk connected to my ipod and made a short recording of audio note. The sound was good.

I've searched the discussion boards and I haven't found any thing about what is causing this. This Plantronics headset uses a USB DSP Audio interface. Any help would be greatly appreciated. Thanks

Paul