grab this file -- http://download.cnet.com/NirCmd/3000-2094_4-77191.html
extract and put into drive c
in notepad type this
C:\nircmd.exe setdefaultsounddevice "TV"
C:\nircmd.exe setprimarydisplay 2
then Save As,
File name-- anything you want.bat
Save as type-- All Files.
("TV" is name of your sound card, you can name it under sound> playback to anything you want.)
("2" this is number assigned to your monitor, go screen resolution and Identify.)
make 2 files like that to switch back and forth.