Effects of Headset, Flight Workload, Hearing Ability, and Communications Message Quality on Pilot Performance

Objective: This study was designed to determine the effects of hearing loss, aviation headset type, flight workload complexity, and communication signal quality on pilots' performance in an army rotary-wing flight simulator. Background: To maintain flight status, army aviators who do not meet current audiometric standards require a hearing loss waiver, which is based on speech intelligibility in quiet conditions. Because hearing loss characteristics of hearing-impaired aviators can vary greatly, and because performance is likely also influenced by degree of flight workload and communication demand, it was expected that performance among hearing-impaired aviators would also vary. Method: Participants were 20 army helicopter pilots. Pilots flew three flights in a full motion-based helicopter simulator, with a different headset configuration and varying flight workload levels and communication signal quality characterizing each flight. Objective flight performance parameters of heading, altitude, and airspeed deviation and air traffic control command read-backs were measured. Results: Statistically significant results suggest that high levels of flight workload, especially in combination with poor communications signal quality, lead to deficits in flight performance and speech intelligibility. Conclusion: These results support a conclusion that factors other than hearing thresholds and speech intelligibility in quiet should be considered when evaluating helicopter pilots' flight safety. The results also support a recommendation that hearing-impaired pilots use assistive communication technology and not fly with strictly passive headsets. Application: The combined effects of flight environment with individual hearing levels should be considered when making recommendations concerning continued aviation flight status and those concerning communications headsets used in high-noise cockpits.