Noise and vibration ride comfort criteria

A program is underway at Langley Research Center to develop a comprehensive ride quality model based upon the various physical and psychological factors that most affect passenger ride comfort. Two of the most important factors, namely vibration and noise, were studied in a previous investigation in which the relative contribution of each factor to overall passenger discomfort was determined. This earlier study utilized a category scale to elicit responses from subjects exposed to combined sinusoidal vibration and octave band noises. The present study is an extension of this work and used a magnitude estimation procedure to obtain subjective responses to combined noise and vibration where the vibration stimuli now included random vibrations. The specific purposes of this paper are to (1) determine the absolute contribution of noise and vibration to passenger discomfort in terms of the discomfort units associated with the ride quality model, and (2) determine if passenger discomfort responses to combined n...