I have an Asus motherboard with a GeForce 550 Ti, connected to a TV over HDMI. The problem is I can't get any sound out of the TV from the computer. However, the command:
aplay -D plughw:NVidia,7 /usr/share/sounds/alsa/Front_Center.wav
Does produce output, the sound comes through the TV fine. I have the latest version of the driver from NVidia installed, and the graphics card shows up fine in system preferences. Any ideas?
Edit: I don't get any sound with OS X Lion (Hackintosh) either, but I can get sound out of both OS's through the built in headphone port.