Accession Number : AD0019388


Title :   FLIGHT DECK NOISE-EXCLUSION PERSONNEL HELMET (FDPH) EVALUATION


Corporate Author : OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS


Personal Author(s) : Tolhurst, Gilbert C ; Morrill, Scott N


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/019388.pdf


Report Date : 07 May 1953


Pagination or Media Count : 29


Abstract : Eight FDP helmets were tested for noise reducing qualities by means of a calibrated condenser microphone placed within a plaster dummy head to simulate the human ear. The attenuation characteristics for each helmet were determined over the audible spectrum at each of 11 discrete frequencies. Two types of sounds were used for the over-all noise level measurements: (1) 124 db of recorded JRB, twin-engine noise and (2) 124 db of American Standard Association white noise. The helmets were not effective in attenuating noise frequencies below 500 cps; the helmet with the greatest mass was the most effective. Occluding the ear canal by a standard ear warden appeared to offer greater protection than any of the helmets.


Descriptors :   *NOISE REDUCTION , *HELMETS , *FLIGHT DECKS , *AIRCRAFT NOISE , MEASUREMENT , HUMANS , SPECTRA , MICROPHONES , EAR , HEARING , LEVEL(QUANTITY) , CALIBRATION , ACOUSTIC ATTENUATION


Subject Categories : Noise Pollution and Control


Distribution Statement : APPROVED FOR PUBLIC RELEASE