Sound Attenuation Evaluation of the Navy's HGU-84/P Helicopter Helmet

摘要

First article sound attenuation tests were conducted on samples of the HGU-84/Phelicopter helmet, candidate replacement for the SPH-3C series of helmets, supplied for evaluation by the Naval Air Warfare Center Aircralt Division, Warminster, Pennsylvania. The tests were conducted in accordance with American National Standard ANSI 512.6-1984, Method for the Measurement of Real-Ear Attenuation of Hearing Protectors. Objective measurements of attenuation, microphone-in-real-ear (MIRE), were also obtained for database and record purposes. Ten Marine Corps student aviators in the Naval Aviation Flight Training Program served as volunteer test subjects. Real-ear attenuation values calculated from measurements made at the nine, one-third octave test frequencies met or exceeded the required minimum real-ear attenuation specifications for the newly developed helmet. This technical memorandum documents the results of the sound attenuation tests. The HGU-84/P helmet is currently being fielded as a replacement for the SPH-3C helmet. (AN).