I plugged my Linux box into the tv

And I didn't have any sound coming through the HDMI cable. I am currently using Lubuntu and everything else worked perfectly. The problem was I wasn't using the Nvidia drivers. I was seriously hoping to avoid using the Nvidia drivers since it doesn't play well with Lubuntu. All my text ends up super small. Therefore I switched to Ubuntu. 

To get sound over HDMI I had to install pavucontrol:

sudo apt-get install pavucontrol

Then select HDMI as the output.

However my login screen still says Lubuntu. To change it to Ubuntu I issued the following command:

sudo update-alternatives - - config default.plymouth 

And selected the Ubuntu option. The to make the changes permanent issue the following command 

sudo update-initramfs -u

Now logging in says Ubuntu :-)