In daily life, people experience whole-body vibrations (WBV) in numerous situations. Many of these vibrations are time-variant, for example in moving vehicles. Signals with close temporal proximity influence the perception of each other. This effect is known as temporal masking. In this paper we will discuss the influence of temporal masking for whole-body vibrations for seated human subjects. Forward and backward masking are compared for two inter-stimulus-intervalls. Backward masking is looked into more detail for 40 Hz with two different target lengths and eight different inter-stimuli-intervals between 20 ms and 520 ms. The effect of temporal masking for WBV decreases with increasing ISI and it is stronger for targets with a shorter duration.