Mäntysalo S, Vuori J
Br J Ind Med. 1984 Feb;41(1):122-32. doi: 10.1136/oem.41.1.122.
In this study the effects on hearing induced by occupational exposure to impulse noise were compared with those induced by exposure to continuous steady state noise. Three groups exposed to impulse noise, one group exposed to continuous steady state noise, and an unexposed control group were studied. The hearing thresholds of the groups were measured by a puretone audiometer three times in two workdays. None of the groups showed significant differences between the hearing thresholds measured in the morning, at midday, and in the afternoon. Group 1 with the shortest duration of exposure and group 2 with the intermediate duration of exposure to impulse noise had the highest thresholds at 6000 Hz in both ears. Group 3 with the longest duration of exposure to impulse noise had the highest thresholds asymmetrically, at 4000 Hz in the left ear and at 6000 Hz in the right ear. The group exposed to continuous steady state noise also had the highest thresholds asymmetrically, in the left ear at 6000 Hz. It was concluded that the longer the duration of exposure to impulse noise the wider the region of the frequencies that showed raised threshold shifts in both ears. Impulse noise seemed to produce permanent threshold shifts at 4000 and 6000 Hz after a shorter duration of exposure than continuous steady state noise.
在本研究中，将职业性接触脉冲噪声所致的听力影响与接触连续稳态噪声所致的听力影响进行了比较。研究了三组接触脉冲噪声的人员、一组接触连续稳态噪声的人员以及一个未接触噪声的对照组。在两个工作日内，用纯音听力计对各组人员的听力阈值进行了三次测量。各组人员在上午、中午和下午测量的听力阈值之间均未显示出显著差异。接触脉冲噪声时间最短的第1组和接触时间中等的第2组在双耳6000Hz处的阈值最高。接触脉冲噪声时间最长的第3组双耳阈值不对称升高，左耳在4000Hz，右耳在6000Hz。接触连续稳态噪声的组双耳阈值也不对称升高，左耳在6000Hz。研究得出结论，接触脉冲噪声的时间越长，双耳出现阈值升高变化的频率范围越宽。与连续稳态噪声相比，脉冲噪声似乎在较短的接触时间后就会在4000Hz和6000Hz处产生永久性阈值变化。
