Brown A M, Gaskill S A
Laboratory of Experimental Psychology, School of Biological Sciences, University of Sussex, Falmer, Brighton, United Kingdom.
J Acoust Soc Am. 1990 Aug;88(2):840-9. doi: 10.1121/1.399733.
The level of 2f1-f2 acoustic distortion product (ADP) measured in the meatus during two-tone stimulation was compared with N 1 thresholds measured at the round window for the guinea pig. A significant inverse relation was found between distortion level and N 1 threshold. A similar relationship has also been reported for ADP level and subjective thresholds in half the human ears measured [S.A. Gaskill and A.M. Brown, J. Acoust. Soc. Am. 88, 821-839 (1990)]. Guinea pig and human ADP levels behave similarly in response to varying stimulus parameters. The ADP levels grow to a maximum and decline with increasing stimulus separation. The decline is steeper in the human ear. In both species, ADP growth as a function of stimulus level is approximately 1 with covaried stimuli; more gradual with the level of f2 (L 2) alone increasing and steeper when the level of f1 (L 1) alone is increased. The latter slopes are strongly influenced by the level of the stationary L 2 and are less steep in the human ear. A link has been proposed between differences in ADP behavior and differences in auditory filter bandwidth in the two species. Guinea pigs show little intersubject variability in ADP level. They do not show the fine structure in distortion level across frequency or the variation in growth rate seen in human responses. Differences in organ of Corti fine structure may underly these differences.
在豚鼠两音刺激期间，测量耳道内2f1 - f2声畸变产物（ADP）的水平，并与圆窗处测量的N1阈值进行比较。发现畸变水平与N1阈值之间存在显著的负相关关系。对于所测量的一半人耳，ADP水平与主观阈值之间也报告了类似的关系[S.A. 加斯基尔和A.M. 布朗，《美国声学学会杂志》88, 821 - 839 (1990)]。豚鼠和人耳的ADP水平在响应不同刺激参数时表现相似。ADP水平随着刺激间隔增加先上升至最大值然后下降。人耳中的下降更为陡峭。在这两个物种中，随着协变刺激，ADP作为刺激水平的函数增长近似为1；仅f2（L2）水平增加时增长较为平缓，而仅f1（L1）水平增加时增长更陡峭。后一种斜率受固定L2水平的强烈影响，并且在人耳中较平缓。已经有人提出，这两个物种中ADP行为的差异与听觉滤波器带宽的差异之间存在联系。豚鼠之间ADP水平的个体差异很小。它们在频率上的畸变水平没有显示出精细结构，也没有显示出人类反应中所见的增长率变化。柯蒂氏器精细结构的差异可能是这些差异的基础。
