Unplug and reconnect the headset. Make sure the connector is pushed in all the way.
Make sure the volume isn’t turned down all the way.
Music on iPhone might be paused. Try pressing the center button on the iPhone headset (or the equivalent button on your Bluetooth headset) to resume playback. Or from the Home screen, tap iPod, tap Now Playing, then tap
.
Check to see if a volume limit is set. From the Home screen choose Settings > iPod > Volume Limit. For more information, see Music.
Make sure you’re using the latest version of iTunes (go to www.apple.com/itunes).
If you’re using the optional dock’s line out port, make sure your external speakers or stereo are turned on and working properly.