Marshall Lynne, Lapsley Miller Judy A., Heller Laurie M.
Naval Submarine Medical Research Laboratory, Groton, CT 06349, USA., Email:
Noise Health. 2001;3(12):43-60.
Noise-induced hearing loss includes both temporary (TTS) and permanent (PTS) threshold shifts. Although TTS and PTS have many similarities, their underlying mechanisms are different. Both TTS and PTS are seen in hearing-conservation programs, making it important to consider both when making physiological measurements of inner-ear damage in applied settings. There are many ways that physiological mechanisms could be useful in screening for NIHL. Can normal-hearing and NIHL ears be differentiated from one another? Can the physiological measure be used in place of behavioural hearing-threshold measures of TTS and PTS? Can it be used to indicate sub-clinical damage (i.e., noise-induced permanent alterations to the inner ear without a corresponding hearing decrement)? Can it be used to indicate pre-clinical hearing loss (i.e., the sub-clinical damage eventually turns into hearing loss)? Finally, can the physiological measure be used to predict susceptibility to NIHL? Evoked otoacoustic emissions (EOAEs) depend on normal outer hair cells for their generation. Because this is the site in the inner ear in humans that is most susceptible to noise, there has been considerable interest in the application of EOAEs to NIHL screening. In this review, the application of distortion-product EOAEs (DPOAEs) is considered for this purpose, emphasizing work from our laboratory, but including that of others as well. Wherever possible, we compare the performance of DPOAEs as a screening tool to transient-evoked otoacoustic emissions (TEOAEs). We emphasize the importance of how well DPOAEs perform in screening for NIHL in individuals rather than for groups of people; the importance of using large numbers of subjects; and the importance of longitudinal studies.
噪声性听力损失包括暂时性（TTS）和永久性（PTS）阈移。尽管TTS和PTS有许多相似之处，但其潜在机制不同。在听力保护计划中都会出现TTS和PTS，因此在应用环境中对内耳损伤进行生理测量时，同时考虑这两者非常重要。生理机制在噪声性听力损失筛查中可能有多种用途。听力正常的耳朵和噪声性听力损失的耳朵能相互区分吗？生理测量能否替代TTS和PTS的行为听力阈测量？它能用于指示亚临床损伤（即噪声引起的内耳永久性改变但无相应听力减退）吗？它能用于指示临床前听力损失（即亚临床损伤最终转变为听力损失）吗？最后，生理测量能用于预测对噪声性听力损失的易感性吗？诱发耳声发射（EOAE）的产生依赖于正常的外毛细胞。由于这是人类内耳中最易受噪声影响的部位，因此人们对将EOAE应用于噪声性听力损失筛查有相当大的兴趣。在本综述中，为此考虑了畸变产物耳声发射（DPOAE）的应用，重点强调我们实验室的工作，但也包括其他实验室的工作。只要有可能，我们就将DPOAE作为筛查工具的性能与瞬态诱发耳声发射（TEOAE）进行比较。我们强调DPOAE在个体而非人群噪声性听力损失筛查中的表现、使用大量受试者的重要性以及纵向研究的重要性。
