Getting video & audio from laptop to TV.

I can get the computer video to play on my non-smart TV but audio will play only on the computer. I want both video and audio to play on the TV. The computer is a HP Probook 6550b laptop. The TV is Insignia NS-55E480A13A. The cable I used to connect them is this. Why does audio play only on the laptop?

Thanks in advance.

Didn’t you already ask this?
http://boards.straightdope.com/sdmb/showthread.php?t=821877

(they answered it there: you need a separate audio cable)

Couldn’t see it so I did another. Reported.

Moderator Action

Since there’s already a thread on this, I’ll go ahead and close this one.