How to connect my laptop sound to my tv?

I am using an HDMI cord and have my laptop connected, but there is no sound. I went to my sound settings and it says that the sound is not connected. My tv is an insignia. It works when I have my PS3 connected to it but has been giving me problems. I tried turning off the tv and turning it back on. unplugging it, resetting my laptop, redo the cord, by unplugging the HDMI cord and such. I had no such luck. Please help!