The audio quality is compromised (distortion, choppy audio, "buzzy" audio).

There are several remedies for audio that is distorted, choppy or otherwise compromised:

1. Hot plug the interface (unplug the USB or Thunderbolt cable, then plug it back in)
2. Toggle sample rate (in your DAW or, in the case of iTunes, Audio MIDI Setup)
3. Reload DAW driver (for example, in Logic choose Logic Pro Preferences Audio. Click on the Devices tab, then the Core Audio tab. Uncheck Enabled, then re-check it.
4. In iTunes, stop then re-start audio playback.