Acton W I, Carson M B
Br J Ind Med. 1967 Oct;24(4):297-304. doi: 10.1136/oem.24.4.297.
This investigation was undertaken primarily to examine the possibility of hearing damage from industrial ultrasonic equipment. In the factory concerned, ultrasonic washers and drills were used at a number of different locations, and girls working 12 ft (3·6 m.) away from one bank of three small washers complained of unpleasant subjective effects which included fatigue, persistent headaches, nausea, and tinnitus. As personnel working in the vicinity of similar washers in other parts of the factory did not complain of these effects, it seemed possible that the noise had been transmitted along a column of air in a bank of dryboxes. Enclosure of these washers by a sliding screen of Perspex had completely abated the trouble. Sound pressure level measurements taken in the positions occupied by the operators indicated that, when the effects occur, they are probably caused by high sound levels at the upper audio-frequencies present with the ultrasonic noise, and this was supported by a limited laboratory investigation. Audiometric investigation showed that hearing damage due to noise from these industrial ultrasonic devices is unlikely. However, extrapolations of currently accepted hearing damage risk criteria may be valid in predicting the occurrence of these subjective effects.
本次调查主要是为了研究工业用超声波设备造成听力损伤的可能性。在所涉工厂中，多个不同地点使用了超声波清洗机和钻孔机，在距离一排三台小型清洗机12英尺（3.6米）远的地方工作的女工抱怨出现了不适的主观症状，包括疲劳、持续头痛、恶心和耳鸣。由于工厂其他区域在类似清洗机附近工作的人员并未抱怨有这些症状，所以似乎有可能是噪声通过一排干燥箱中的空气柱传播的。用有机玻璃滑动屏风将这些清洗机围起来后，问题完全消除了。在操作员所在位置进行的声压级测量表明，出现这些症状时，可能是由超声波噪声中存在的高频声音的高声级引起的，有限的实验室调查也证实了这一点。听力测定调查表明，这些工业用超声波设备产生的噪声导致听力损伤的可能性不大。然而，目前公认的听力损伤风险标准的推断可能有助于预测这些主观症状的出现。
