I'm playing halo 3 on my xbox and...?

[ridelaughlove]

I'm playing with other people through live. I'm using a wireless headset. I can hear people and talk to them through it, but sometimes I hear them talking through my tv speakers. I don't want this. How can I fix it so I can only hear them through the headset?

 

[Madd Skillz]

Start Button > Scroll to Right > Voice Communication > Proximity Voice > Off(or Headset only)