I just bought a Turtle Beach X12 headset....

I'm pretty happy with it. The only thing that's a little annoying is when there's no sound coming through the headset, you hear a little hissing sound. Is that normal? This is the first headset I ever bought so I'm a noob with these things. Is there a problem with the connection or is it a normal thing for the hissing sound?

and is it worth it to get that adapter that makes it surround sound? It costs more than the headset itself

go to the audio board.

Could be a noise canceling feature. Active noise canceling puts out white noise in the background to black out, outside noise.