The Combined Effects of Vibration, Noise, and Exposure Duration on Auditory Temporary Threshold Shift
The Combined Effects of Vibration, Noise, and Exposure Duration on Auditory Temporary Threshold Shift

Author: Henry C. Sommer

Publisher:

Published: 1973

Total Pages: 20

ISBN-13:

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To determine the combined effects of noise and vibration on auditory function, the temporary threshold shifts (TTS) of two groups of 10 subjects each were measured as a function of intensity and duration of exposure. Combined noise and vibration was presented to one group for 5 minutes and to the other for 20 minutes. Both groups were exposed to vibration in the Z axis at frequencies of 9 Mz and 18 Hz at intensity levels of 0.475 gz (peak) and 0.950 gz, respectively. Noise levels of 90 dB and 100 dB were presented simultaneously with the vibration. TTS was measured at post exposure recovery times of 0.5, 2.0, 5.0, 10.0, and 20.0 minutes. Although the mean difference was small (0.72 dB), a significantly larger TTS was obtained at 9 Hz than 18 Hz vibration, and 100 dB produced a larger TTS than 90 dB. Significant differences in TTS were also obtained as a function of duration of exposure, and as a function of post exposure recovery time. (Modified author abstract).

Combined Effects of Noise and Vibration on Psychomotor Performance
Combined Effects of Noise and Vibration on Psychomotor Performance

Author: C. Stanley Harris

Publisher:

Published: 1970

Total Pages: 29

ISBN-13:

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Tracking performance and reaction time to the appearance of a light (red lights) and disappearance of a light (green lights) of highly trained subjects were measured during four experimental conditions. There were two conditions of 85 dB and 110 dB broadband noise exposure, and two conditions in which these noise exposures were combined with 0.25G vertical vibration at 5 Hz. Duration of exposure for each condition was 19 minutes. Vibration was found to have an adverse effect on both the horizontal and vertical dimensions of the tracking task and on reaction time to both sets of lights. Noise had a significant effect, both with and without vibration, but only on the vertical part of the tracking task. On vertical tracking, the detrimental effect of noise was additive to that of vibration when both noise and vibration were presented simultaneously (110dB noise and 0.25G vertical vibration at 5 Hz). (Author).

Combined Effects of Noise and Vibration on Mental Performance as a Function of Time of Day
Combined Effects of Noise and Vibration on Mental Performance as a Function of Time of Day

Author: Henry C. Sommer

Publisher:

Published: 1970

Total Pages: 15

ISBN-13:

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To determine the combined effects of noise and vibration on mental performance as a function of time of day, subjects were randomly exposed to each of the following conditions: stress (5 Hz vibration, 110 dB noise) at 6 AM; no stress (no vibration - 85 dB noise) at 6 AM; stress at 3 PM; and no stress at 3 PM. Subjects' performance on a mental arithmetic task was measured during each of these exposures on consecutive days. The average exposure time was approximately 20 minutes. The results are discussed in the context of arousal theory. (Author).

The Effects of Whole-Body Vibration
The Effects of Whole-Body Vibration

Author: Heinrich Dupuis

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 183

ISBN-13: 3642712452

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The observations made by Paracelsus concerning the dose-effect relationship of poison are generally just as applicable to health threatening vibration. With regard to kind, intensity, and duration of the vibration, the "dose" is decisive as to whether the conse quences are detrimental, unmeaningful, or tolerable with respect to health. This law of nature determines the tasks and goals of those whose aim is to safeguard health. Researchers worldwide have been occupying themselves with this many-faceted question for some time: how mechanical vibration affects the human organism and at what point damage occurs. If prevention in occupational medicine is to succeed, it is most important that the gaps in our present knowledge be closed, for if technical preventive measures are to be effective and preventive means in occupational medicine successful, they must be based on reliable and complete findings. Whenever many independent researchers have worked in a given field for a long period, a comprehensive intermediate as sessment is appropriate to evaluate the level achieved and the direction the research is going. In the area of hand-arm vibration, this evaluation has already been carried out, and the response aroused by this particular research report had led to a demand for a comparable evaluation of the research results on whole-body vibration. This report presents clearly and exhaustively the current status of international knowledge, as well as the questions that remain to be answered.