Isoresponse Versus Isoinput Estimates of Cochlear Filter Tuning
Isoresponse Versus Isoinput Estimates of Cochlear Filter Tuning
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DOI：
10.1007/s10162-010-0252-1
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发表时间：
2011-06-01
影响因子：
2.4
通讯作者：
Lopez-Poveda, Enrique A.
中科院分区：
文献类型：
--
作者：
Eustaquio-Martin, Almudena;Lopez-Poveda, Enrique A.
线性滤波器的调谐可以从滤波器的等响应（例如，调谐曲线）或等输入（例如，等值线）特性。本文提供了一个理论证明，对于非线性滤波器的压缩响应特性，如那些基底膜，isoresponse措施可以建议比isoinput措施明显更尖锐的调谐。这一现象的实际意义是通过从正弦和陷波噪声正向掩蔽获得的行为isoresponse和isoinput测量中推断500和4，000 Hz处人类听觉滤波器的3 dB下行带宽（BW 3dB）来证明的。推断耳蜗反应压缩的两种类型的掩蔽。与预期一致，从等响应条件获得的低电平BW 3dB估计值比从等电平条件获得的低电平BW 3dB估计值窄得多：在500 Hz时分别为69与174 Hz，在4，000 Hz时分别为280与464 Hz。此外，isoresponse BW3dB随着水平的增加而降低，而相应的isolevel估计值在500 Hz时保持近似恒定，或在4 kHz时略有增加。建议在比较等反应阈上人类调谐和阈动物神经调谐时应谨慎。
The tuning of a linear filter may be inferred from the filter's isoresponse (e.g., tuning curves) or isoinput (e.g., isolevel curves) characteristics. This paper provides a theoretical demonstration that for nonlinear filters with compressive response characteristics like those of the basilar membrane, isoresponse measures can suggest strikingly sharper tuning than isoinput measures. The practical significance of this phenomenon is demonstrated by inferring the 3-dB-down bandwidths (BW3dB) of human auditory filters at 500 and 4,000 Hz from behavioral isoresponse and isoinput measures obtained with sinusoidal and notched noise forward maskers. Inferred cochlear responses were compressive for the two types of maskers. Consistent with expectations, low-level BW3dB estimates obtained from isoresponse conditions were considerably narrower than those obtained from isolevel conditions: 69 vs. 174 Hz, respectively, at 500 Hz, and 280 vs. 464 Hz, respectively, at 4,000 Hz. Furthermore, isoresponse BW3dB decreased with increasing level while corresponding isolevel estimates remained approximately constant at 500 Hz or increased slightly at 4 kHz. It is suggested that comparisons between isoresponse supra-threshold human tuning and threshold animal neural tuning should be made with caution.