If the microphones on the WF-1000XM4 earbud headphones 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 occur, remove your hands from the microphones.
The earbuds are equipped with a function to detect a beeping sound (feedback) that will cancel the sound for a short period of 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 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.