Perception of fore-and-aft whole-body vibration intensity measured by two methods.

This experimental study investigated the perception of fore-and-aft whole-body vibration intensity using cross-modality matching (CM) and magnitude estimation (ME) methods. Thirteen subjects were seated on a rigid seat without a backrest and exposed to sinusoidal stimuli from 0.8 to 12.5 Hz and 0.4 to 1.6 ms(-2) r.m.s. The Stevens exponents did not significantly depend on vibration frequency or the measurement method. The ME frequency weightings depended significantly on vibration frequency, but the CM weightings did not. Using the CM and ME weightings would result in higher weighted exposures than those calculated using the ISO (2631-1, 1997) Wd. Compared with ISO Wk, the CM and ME-weighted exposures would be greater at 1.6 Hz and lesser above that frequency. The CM and ME frequency weightings based on the median ratings for the reference vibration condition did not differ significantly. The lack of a method effect for weightings and for Stevens exponents suggests that the findings from the two methods are comparable.
Practitioner Summary: Frequency weighting curves for seated subjects for x-axis whole-body vibration were derived from an experiment using two different measurement methods and were compared with the Wd and Wk weighting curves in ISO 2631-1 (1997).