I took this from the hauppauge site - hope it helps.
You can email if you want.
Make sure you have the latest version of the WinTV software, if you are using CD version 3.4 or older please install the latest version from the following location.
click here, then follow the steps on enabling audio over USB:
If have installed the your WinTV USB device with CD version 3.6 or above please follow the below steps:
WinTV-USB/USB FM, Enabling Audio over USB
After you complete the WinTV-USB driver installation, the default Audio setting is Digital Rec/Analog live.
This default setting requires the supplied double ended stereo cable to be connected from the Line-Out on the WinTV-USB to the Line-In on your sound card.
To enable the audio over USB, click on the Menu button and go to Audio Type and select Digital Rec+Live.
Last, you will be asked to Restart the WinTV application to have the changes take effect.