It's possible that you have the sound playback defaulted as the USB Audio. Follow these steps to correct this:
1. Go into your control panel
2. Go into your sound and audio devices
3. Click on the Audio Tab
4. Default your sound recording to the USB Audio Codec
5. Default your sound playback to the sound card you are using. (either built-in computer playback, connected speakers or audio interface)
(These steps are also in the owner's manual.)