Hi,
I had a problem where my brand new turtle beaches could hear people in game chat when I was in a private chat or Party chat. This was very annoying and I soon looked into it. If you are having these problems on xbox360, do the following:
Xbox 360 Settings
1. On the Xbox (not Xbox LIVE) go to dashboard "System Settings" and
press "A" button on your controller.
2. Scroll down to "Console Settings" and press "A" again.
3. Select "Audio" then "Digital Output", pressing the "A" button to
view each menu, and change the setting from "Dolby" to "Dolby
Digital with WMA Pro."
Hopefully my instructions will help you!