This works and came straight from the link below.
"All you have to do is connect the cable and get (the) picture coming through the TV, and then right click on your sound settings in the bottom right, next to your clock. Click on 'Playback Devices' you should have an option for 'SPDIF Interface'. Single left-click on it and underneath next to properties click on 'Set Default'.
Now close your Youtube, or browser, or music program or anything active that sends out sound and restart your youtube or whatever and you'll get sound through your TV."
DV2500t No sound from HDMI - Notebook Forums and Laptop Discussion