Abdala C, Sininger Y S, Ekelid M, Zeng F G
House Ear Institute, Children's Auditory Research and Evaluation Center, Los Angeles, CA 90057, USA.
Hear Res. 1996 Sep 1;98(1-2):38-53. doi: 10.1016/0378-5955(96)00056-1.
Distortion product otoacoustic emission (DPOAE) iso-suppression tuning curves (STC) were generated in 15 normal-hearing adults and 16 healthy term-born neonates for three f2 frequencies. The 2f1-f2 DPOAE was elicited using f2/f1 = 1.2, LI = 1.2, LI = 65 and L2 = 50 dB SPL. A suppressor tone was presented at frequencies ranging from 1 octave below to 1/4 octave above f2 and varied in level until DPOAE amplitude was reduced by 6 dB. The suppressor level required for 6 dB suppression was plotted as function of suppressor frequency to generate a DPOAE STC. Forward-masked psychoacoustic tuning curves (PTC) were obtained for three of the adult subjects. Results indicate that DPOAE STCs are stable and show minimal inter- and intra-subject variability. The tip of the STC is consistently centered around the f2 region and STCs are similar in shape, width (Q10) and slope to VIIIth-nerve TCs. PTCs and STCs measured in the same subject showed similar trends, although PTCs had narrower width and steeper slope. Neonatal STCs were recorded at 3000 and 6000 Hz only and were comparable in shape, width and slope to adult STCs. Results suggest: (1) suppression of the 2f1-f2 DPOAE may provide an indirect measure of cochlear frequency resolution in humans and (2) cochlear tuning, and associated active processes in the cochlea, are mature by term birth for at least mid- and high-frequencies. These results provide significant impetus for continued study of DPOAE suppression as a means of evaluating cochlear frequency resolution in humans.
在15名听力正常的成年人和16名足月出生的健康新生儿中，针对三个f2频率生成了畸变产物耳声发射（DPOAE）等抑制调谐曲线（STC）。使用f2/f1 = 1.2、L1 = 1.2、L1 = 65和L2 = 50 dB SPL引出2f1 - f2 DPOAE。在低于f2一个倍频程到高于f2四分之一倍频程的频率范围内呈现抑制音，并改变其强度，直到DPOAE幅度降低6 dB。将6 dB抑制所需的抑制音强度作为抑制音频率的函数进行绘制，以生成DPOAE STC。对三名成年受试者获得了前掩蔽心理声学调谐曲线（PTC）。结果表明，DPOAE STC是稳定的，受试者间和受试者内的变异性最小。STC的尖端始终围绕f2区域居中，并且STC在形状、宽度（Q10）和斜率方面与第八对脑神经调谐曲线相似。在同一受试者中测量的PTC和STC显示出相似的趋势，尽管PTC的宽度更窄且斜率更陡。仅在3000和6000 Hz记录了新生儿的STC，其形状、宽度和斜率与成人的STC相当。结果表明：（1）对2f1 - f2 DPOAE的抑制可能为人类耳蜗频率分辨率提供一种间接测量方法；（2）耳蜗调谐以及耳蜗中相关的主动过程在足月出生时至少对于中高频已经成熟。这些结果为继续研究DPOAE抑制作为评估人类耳蜗频率分辨率的一种手段提供了重要动力。
