Manikin Measurements of the Noise Attenuation Provided by Flight Helmets Free

To determine the noise attenuation provided by various flight helmets according to the USASI Standard for the Evaluation of Real‐Ear Attenuation at Threshold consumes a considerable amount of time. A manikin head has been developed to serve as a tool for assisting in such evaluations. Its use must be considered in terms of the particular requirements for a given evaluation program. With a manikin head, a helmet can be optimally fitted and reliable data obtained in approximately 3 to 5 min. Variability introduced by human factors is kept at a minimum. High levels of noise can be used as the test stimulus. Visual and auditory monitoring of the attenuated noise provides the experimenter with a precise appraisal of the fit as adjustments are made. The manikin method of measurement also reveals improvements in attenuation resulting from minor modifications. Measurements of attenuation for five flight helmets by the manikin method were very similar to measurements obtained by the real‐ear method. In‐flight manikin measurements of attenuation will also be discussed. [Work supported by NAVAIRSYSCOM.]