On November 20, 2015, the FAA issued a Special Airworthiness Information Bulletin (SAIB CE-16-08) that advises GA pilots and operators of concerns with the use of noise cancelling headsets. In many cases, pilots are using the noise cancelling headsets as supplementary equipment during operations. When wearing these headsets, the pilot may be unaware of environmental sounds and audible warning annunciations in the cockpit that do not come through the intercom system.
The FAA recommends that if any audible alarms or environmental sounds cannot be discerned, operators should elect to find other solutions to discern such alarms or sounds, or discontinue the use of noise-canceling headsets. The agency also recommends pilots review the information found in an earlier bulletin (InFO 07001) on noise-cancelling headset use which can be accessed at http://go.usa.gov/cZdDz.