How do I use my BlueTooth on the Ps3?

[Branden - AN AMERICAN!!!]

I went to accessories, registered my T-Mobile Bluetooth headset, then connected it, and when I go on Call of Duty: Modern Warfare it show a little speaker next to my name or anything and nobody can hear me.

What do I do?

 

[The Shadow Knows]

COD 4 is picky about which headsets it likes
I would get the Sony PS3 one as it works with all games