Hearing and Noise in Aviation

2006PDFTech ReportAM-400-98/3Auditory perceptionNoiseAir pilotsAviation medicinePhysiologyNoise sourcesCivil aviationAnatomyFrequencyNoise exposureAuditory systemSoundHearingUnited StatesUnited States. Federal Aviation AdministrationAntunano, Melchor J.Spanyers, James P.United States. Federal Aviation AdministrationCivil Aerospace Medical InstituteUS Transportation CollectionHearing is second only to vision as a sensory mechanism to obtain critical information during the operation of an aircraft. All sounds have three distinctive variables: frequency, intensity, and duration. Normal conversation takes place in the frequency range from 500 to 3,000 Hz. Daily exposure to noise levels higher than 90dB can cause hearing impairment. This can go unnoticed initially because it occurs in the vicinity of 4,000 Hz (outside the conversational range). If the ambient noise level reaches 90dBA, you must use hearing protection equipment to prevent hearing impairment. Exposure to loud noise before flying (at home, while driving, at a party, etc.) can be as harmful as exposure to aircraft noise.73