Department of Neurosurgery, University of Minnesota, Minneapolis, MN 55455, USA.
Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
Hear Res. 2022 Jul;420:108500. doi: 10.1016/j.heares.2022.108500. Epub 2022 Mar 31.
Behavioral forward-masking thresholds with a spectrally notched-noise masker and a fixed low-level probe tone have been shown to provide accurate estimates of cochlear tuning. Estimates using simultaneous masking are similar but generally broader, presumably due to nonlinear cochlear suppression effects. So far, estimates with forward masking have been limited to frequencies of 1 kHz and above. This study used spectrally notched noise under forward and simultaneous masking to estimate frequency selectivity between 200 and 1000 Hz for young adult listeners with normal hearing. Estimates of filter tuning at 1000 Hz were in agreement with previous studies. Estimated tuning broadened below 1000 Hz, with the filter quality factor based on the equivalent rectangular bandwidth (Q) decreasing more rapidly with decreasing frequency than predicted by previous equations, in line with earlier predictions based on otoacoustic-emission latencies. Estimates from simultaneous masking remained broader than those from forward masking by approximately the same ratio. The new data provide a way to compare human cochlear tuning estimates with auditory-nerve tuning curves from other species across most of the auditory frequency range.
使用带频谱凹陷噪声掩蔽器和固定低声压探测音的行为前向掩蔽阈值已被证明可以准确估计耳蜗调谐。使用同时掩蔽进行的估计相似，但通常更宽，这可能是由于耳蜗的非线性抑制效应。到目前为止，前向掩蔽的估计仅限于 1 kHz 及以上的频率。本研究使用前向和同时掩蔽下的频谱凹陷噪声，为具有正常听力的年轻成年听众在 200-1000 Hz 之间估计频率选择性。在 1000 Hz 处的滤波器调谐估计与先前的研究一致。在 1000 Hz 以下，调谐变宽，基于等效矩形带宽 (Q) 的滤波器品质因数的下降速度比先前的方程预测的更快，与基于耳声发射潜伏期的早期预测一致。同时掩蔽的估计比前向掩蔽的估计宽约相同的倍数。新数据提供了一种方法，可以将人类耳蜗调谐估计与来自其他物种的听觉神经调谐曲线在听觉频率范围内的大部分进行比较。
