Davis R I, Ahroon W A, Hamernik R P
Auditory Research Laboratories, State University of New York, Plattsburgh.
Hear Res. 1989 Aug;41(1):1-14. doi: 10.1016/0378-5955(89)90173-1.
Evoked-potential tuning curves were obtained on over 150 chinchillas before and after acoustic overstimulation in order to relate the effects of changes in frequency selectivity to sensory cell loss over a wide range of hearing loss. Pre- and post-exposure measures of auditory thresholds and masked thresholds (simultaneous tone-on-tone paradigm) were obtained in each animal at 0.5, 1.0, 2.0, 4.0, 8.0 and 11.2 kHz, using the auditory evoked potential recorded from the inferior colliculus. Three tuning curve variables (Q10dB, low-frequency slope and high-frequency slope) were compared to the amount of noise-induced permanent threshold shift and to the percent sensory cell loss produced by a variety of noise exposures. Based upon large sample averages, frequencies showing permanent threshold shifts in excess of 10 dB also showed statistically significant differences between pre- and post-exposure measures of all three tuning curve variables. Shifts of less than 10 dB were not accompanied by statistically significant changes in the tuning curve variables. The percentage of outer hair cell loss, and percentage change in tuning curve characteristics showed systematic and parallel increases as threshold shifts increased at all probe tone frequencies except 8.0 and 11.2 kHz. In general, the results were consistent in showing that there is a systematic change in the variables which define the quality of tuning as hearing loss progressively increases and that these changes are clearly related to outer hair cell losses.
为了研究在广泛的听力损失范围内频率选择性变化的影响与感觉细胞损失之间的关系，在150多只毛丝鼠身上进行了声刺激过度刺激前后的诱发电位调谐曲线测试。使用从下丘记录的听觉诱发电位，在每只动物的0.5、1.0、2.0、4.0、8.0和11.2kHz频率处获得暴露前和暴露后的听觉阈值和掩蔽阈值（同时纯音对纯音范式）测量值。将三个调谐曲线变量（Q10dB、低频斜率和高频斜率）与噪声诱发的永久性阈值偏移量以及各种噪声暴露导致的感觉细胞损失百分比进行比较。基于大量样本平均值，显示永久性阈值偏移超过10dB的频率在所有三个调谐曲线变量的暴露前和暴露后测量值之间也显示出统计学上的显著差异。小于10dB的偏移在调谐曲线变量中没有伴随统计学上的显著变化。除了8.0和11.2kHz之外，在所有探测音频率下，随着阈值偏移增加，外毛细胞损失百分比和调谐曲线特征的百分比变化显示出系统性的平行增加。总体而言，结果一致表明，随着听力损失逐渐增加，定义调谐质量的变量存在系统性变化，并且这些变化与外毛细胞损失明显相关。
