Can't get sound through HDTV via laptop.

Hello,
I'm attempting to stream video and sound through my TV, my VGA > VGA cable works fine and I get picture though no sound.

I've got a 3.5mm jack to a 3.5mm jack which I've connected and have had no luck also an RCA to 3.5mm which did not give me any sound, is there some setting I'm missing or am I using the wrong inputs on the TV?

This has got me very frustrated and I've given up for now hoping for some help.