Time and magnitude dependent masking effects of vehicle's 2 Hz shock type vibrations on the perception of vehicle's 4.5 Hz longitudinal shock type vibrations for seated human subjects

In the literature there are no known studies regarding temporal masking effects of a vehicle's shock type vibrations. Since shock type vibrations of different directions of movement, magnitudes and frequencies are acting on the human body while driving a vehicle, temporal masking effects may be relevant when evaluating a vehicle's ride comfort. This study investigates temporal post-masking effects of a vehicle's 2 Hz shock type vibrations (masker) on the perception of 4.5 Hz longitudinal shock type vibrations (test signal) for the seated human body. It was found that post-masking exists for the investigated vibrations. The masking effect is highly dependent on the time gap between masker and test signal: with increasing time gap the masking effect decreases. Furthermore the amount of masking increases with increasing masker magnitude. Both findings are consistent with the findings in psychoacoustics. In addition to that the masking effect depends on the masker's direction of movement.