噪声暴露对全身振动感知阈值的影响

尽管对全身振动感知阈值已有人做过一些试验研究，但是对于暴露于噪声条件下的感知阈值尚无相关试验．但此项研究是很重要的，因为许多振动源往往同时也激发产生噪声．文中通过一项试验来探讨噪声对身体振动感知阂值的影响．共有10位受试者坐在固定于垂直振动台的椅子上，被要求自行调节振动级来确定阈值．采用4种正弦波形的振动以及随机振动作为刺激，同时采用以10dB作为调节量的随机噪声作为刺激．试验发现阈值随着噪声级的增加而增加．这意味着随噪声级的增加，人体对振动的敏感度下降了．尽管此中的原因尚不明晰，但文中对同一频率下听觉与振动感觉之间的相互影响提出了建议．

Effects of Noise Exposure on Whole-Body Vibration Perception Threshold

Although several experiments on whole-body vibration perception thresholds have so far been conducted in the world, no experiment on those under the conditions of noise exposure has been done. It is important to know the vibration perception thresholds of people who are exposed to noise because many vibration sources cause noises simultaneously. An experiment was performed to examine the effects of noise exposure on whole-body vibration perception thresholds. Ten subjects sitting on a chair fixed on a vertical vibration table were requested to adjust the vibration level to detect the threshold. Four sinusoidal vibrations and a random vibration were used as test stimuli, and 10 dB step random noises were presented simultaneously for each vibration stimulus. It is found that the thresholds increase with the noise exposure levels. This means that the sensitivity to whole-body vibration decreases as noise exposure increases. Although the reason for this result is unascertained, the interaction between the auditory sensation and the vibration sensation at the same frequencies is suggested.