The X3 microphone may be used to communicate with other players during Xbox 
Live multi-player gaming sessions. Use the included cable to connect the
headphones to the Xbox 360 controller as illustrated below.

  
 
USING THE MICROPHONE:
  The microphone signal connects to the Xbox controller via the cable plugged 
  into the headphones. The mute switch on the "puck" plugged into the Xbox 
  controller can be used to silence the microphone when you don't want to 
  be heard. 

  For optimum clarity, adjust the microphone so that it is situated a few 
  inches away from your mouth. The X3 mixes a portion of the microphone signal
  into the headphone signal, so you can hear some of your voice along with the
  online chatting and game audio.
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