Zurek P M, Clark W W, Kim D O
J Acoust Soc Am. 1982 Sep;72(3):774-80. doi: 10.1121/1.388258.
Acoustic intermodulation distortion products were measured in 15 ear canals of chinchillas with normal or damaged ears. Pretreatment results showed that when two primary tones at frequencies f1 and f2, f1 less than f2, were presented at levels from 30 to 90 dB SPL, acoustic distortion products at 2f1-f2 and 2f2-f1 were 30 to 50 dB below primary-tone levels. Noise exposures that caused temporary or permanent hearing loss produced corresponding temporary or permanent reductions in distortion-product levels. Mechanical damage to the cochlea or middle ear reduced the distortion-product levels to below the noise floor of the measurement system. Comparisons of distortion-product level with behaviorally measured threshold shift and cochlear histopathology suggest that, in the absence of conductive impairment, the level of 2f1-f2 or 2f2-f1 can be used as a sensitive indicator of hearing sensitivity and the condition of the cochlea.
在15只耳朵正常或受损的龙猫的耳道中测量了声互调失真产物。预处理结果表明，当频率为f1和f2（f1小于f2）的两个基音以30至90 dB SPL的水平呈现时，2f1 - f2和2f2 - f1处的声失真产物比基音水平低30至50 dB。导致暂时性或永久性听力损失的噪声暴露会使失真产物水平相应地暂时或永久降低。耳蜗或中耳的机械损伤会使失真产物水平降低到测量系统的本底噪声以下。将失真产物水平与行为测量的阈值偏移和耳蜗组织病理学进行比较表明，在没有传导性损伤的情况下，2f1 - f2或2f2 - f1的水平可作为听力敏感度和耳蜗状况的敏感指标。
