Marshall Lynne, Lapsley Miller Judi A, Heller Laurie M, Wolgemuth Keith S, Hughes Linda M, Smith Shelley D, Kopke Richard D
Naval Submarine Medical Research Laboratory, Groton, Connecticut 06349-5900, USA.
J Acoust Soc Am. 2009 Feb;125(2):995-1013. doi: 10.1121/1.3050304.
Audiometric thresholds and otoacoustic emissions (OAEs) were measured in 285 U.S. Marine Corps recruits before and three weeks after exposure to impulse-noise sources from weapons' fire and simulated artillery, and in 32 non-noise-exposed controls. At pre-test, audiometric thresholds for all ears were <or=25 dB HL from 0.5 to 3 kHz and <or=30 dB HL at 4 kHz. Ears with low-level or absent OAEs at pre-test were more likely to be classified with significant threshold shifts (STSs) at post-test. A subgroup of 60 noise-exposed volunteers with complete data sets for both ears showed significant decreases in OAE amplitude but no change in audiometric thresholds. STSs and significant emission shifts (SESs) between 2 and 4 kHz in individual ears were identified using criteria based on the standard error of measurement from the control group. There was essentially no association between the occurrence of STS and SES. There were more SESs than STSs, and the group of SES ears had more STS ears than the group of no-SES ears. The increased sensitivity of OAEs in comparison to audiometric thresholds was shown in all analyses, and low-level OAEs indicate an increased risk of future hearing loss by as much as ninefold.
对285名美国海军陆战队新兵在暴露于武器射击和模拟火炮的脉冲噪声源之前及之后三周测量了听力阈值和耳声发射（OAE），并测量了32名未暴露于噪声的对照组人员。在预测试时，所有耳朵在0.5至3千赫的听力阈值≤25分贝听力级（dB HL），在4千赫时≤30分贝HL。预测试时OAE水平低或无OAE的耳朵在测试后更有可能被归类为有显著阈值变化（STS）。一个由60名双耳有完整数据集的噪声暴露志愿者组成的亚组显示OAE幅度显著下降，但听力阈值无变化。使用基于对照组测量标准误差的标准确定个体耳朵在2至4千赫之间的STS和显著发射变化（SES）。STS和SES的发生之间基本上没有关联。SES比STS更多，SES耳朵组中的STS耳朵比无SES耳朵组更多。在所有分析中均显示OAE相对于听力阈值的敏感性增加，低水平OAE表明未来听力损失风险增加多达九倍。
