If the headphone microphones are covered with your hands, the effect of the Noise Canceling feature, Ambient Sound Mode, or Speak-to-Chat mode may not work properly, or a beeping sound (feedback) may occur. If any of these happen, remove your hands from the microphones.
Note: Some headphones are equipped with a function to detect a beeping sound (feedback) that will cancel the sound for a short time. In rare cases, the Noise Canceling feature, Ambient Sound Mode, or Speak-to-Chat mode may temporarily stop in reaction to a high note such as an alarm, sirens, or an electronic sound (feedback), but the Noise Canceling function or Ambient Sound Mode will automatically return in about a second. This is not a malfunction. If the Ambient Sound Mode doesn't return automatically, try restarting the headphones.