Manninen O, Ekblom A
Int Arch Occup Environ Health. 1984;54(1):1-17. doi: 10.1007/BF00378724.
In the present study the changes in the TTS2 values and body upright posture sway were examined after exposure of subjects (n = 10) to stable broadband (white) noise (90 dB) alone, to sinusoidal vibration alone [directed vertically at the whole body (Z axis)], and to simultaneous exposure combinations of noise and vibrations of the same type. The frequency of the vibration was 5 Hz, but its acceleration was either 2.12 or 2.44 m/s2. There were six exposure combinations, and subsequently 60 tests were carried out in an exposure chamber. One test consisted of a control period of 30 min, of three consecutive exposure periods of 16 min each and of a recovery period of 15 min. After the three exposure combinations which included noise, half of the subjects were exposed to vibration during the recovery period. Apart from indicating an increase in the temporary hearing threshold, the results showed that simultaneous exposure to noise and vibration increases the instability of the body upright posture. The TTS2 values at the 4 and 6 kHz frequencies increased considerably more rapidly when the subjects were exposed simultaneously to noise and vibration than when exposed to noise alone. Without exception, the TTS2 values increased most during the first exposure period. It was noteworthy that exposure to vibration during the recovery period accelerated the recursion of the TTS2 values, especially in cases where the subjects had been exposed to noise alone. The variance of the body sway amplitudes and the standard deviation increased within the frequency range 0.063-2.000 Hz owing to noise alone and simultaneous noise and vibration. In the directions X and Y, within the frequency ranges 0.063-0.100 Hz and 0.100-0.600 Hz, the means of the maximum amplitudes of body sway increased especially in connection with those tests in which the subjects had been simultaneously exposed to noise and vibration.
在本研究中，对10名受试者进行如下处理后，检测了TTS2值和身体直立姿势摇摆的变化：单独暴露于稳定的宽带（白）噪声（90分贝），单独暴露于正弦振动[垂直作用于全身（Z轴）]，以及同时暴露于相同类型的噪声和振动组合。振动频率为5赫兹，但其加速度为2.12或2.44米/秒²。共有六种暴露组合，随后在暴露室内进行了60次测试。一次测试包括30分钟的对照期、三个连续的各16分钟的暴露期和15分钟的恢复期。在包括噪声的三种暴露组合之后，一半受试者在恢复期暴露于振动。结果除了表明临时听力阈值增加外，还显示同时暴露于噪声和振动会增加身体直立姿势的不稳定性。当受试者同时暴露于噪声和振动时，4千赫和6千赫频率处的TTS2值比仅暴露于噪声时增加得快得多。无一例外，TTS2值在第一次暴露期增加最多。值得注意的是，在恢复期暴露于振动会加速TTS2值的恢复，尤其是在受试者仅暴露于噪声的情况下。仅噪声以及噪声和振动同时作用时，身体摇摆幅度的方差和标准差在0.063 - 2.000赫兹频率范围内增加。在X和Y方向上，在0.063 - 0.100赫兹和0.100 - 0.600赫兹频率范围内，身体摇摆最大幅度的平均值尤其在受试者同时暴露于噪声和振动的那些测试中增加。
