A usb speaker is attached to my laptop (OS X 10.8.3). When I plug in a headphone to my Macbook, the audio doesn't automatically get routed to the headphone. I have to manually select the "Headphone" option under Sound preferences. And when I unplug the headphones, the audio doesn't revert to the USB speakers. Instead, the audio goes back to the internal speaker. I have to go back to Sound preference panels and change the output device to USB speaker. Is there any way I could make the transition between USB speakers and headphones more seamless?