A Comparison of Judgments of Vibration Intensity for Chest-to-Back (X Axis) and Side-to-Side (Y Axis) Exposures.

摘要

The subjective intensity of vibration in the two primary horizontal axes (X axis,chest-to-back;and Y axis,side-to-side) was compared through an intensity matching procedure. Unrestrained seated subjects matched their judgments of vibration intensity in one axis (X or Y) by adjusting the intensity of vibration in the other axis until it was subjectively equal to the first. Each of eight subjects made a series of intensity judgments which were counterbalanced so that half of the matches were with an X-axis stimulus and a Y-axis response,and the other half were with a Y-axis stimulus and an X-axis response. Vibration was sinusoidal at 5, 7, 10, 15, 20,and 30Hz. Peak accelerations at each frequency ranged from a lower limit of 0.1g to upper limits of 0.5to 1.3g (depending on frequency). Each vibration stimulus had a duration of 20seconds. Results showed that,within the limits of the vibration parameters sampled, X-axis vibration was judged to be slightly but consistently more intense than Y-axis vibration. (Modified author abstract)