The idea is simple enough: What you don’t hear could kill you. The Flight Standards Service last week released an InFO to alert operators that “noise-canceling” headsets might be susceptible to “misdetection” and subsequent electronic attenuation of some things you’d probably rather hear. (Note: The memo might also pertain to what many pilots refer to as active noise reduction [ANR] headsets, but that specific verbiage was not used.) The alert states that the range of frequencies attenuated by a noise-canceling headset is often proprietary and may not be publicly available. This makes it “difficult to assess any effects” of attenuation, particularly as they pertain to things like communications, abnormal mechanical noises, audible alarms, vibrations, wind noises and other sounds that might alert an unattenuated observer to impending doom. For now, rather than regulate, the FAA’s solution involves passing the buck to you. The FAA recommends operators pursue evaluation of headsets — both in the air and on the ground — sufficient to ascertain any potentially negative effects of the headsets. Further, if any audible alarms or environmental sounds cannot be discerned, efforts should be made to find a different headset. The FAA an identifies an InFO as “valuable information for operators that should help them meet certain administrative, regulatory, or operational requirements with relatively low urgency or impact on safety.”
