REPRESENTATION OF STEADY-STATE VOWELS IN THE TEMPORAL ASPECTS OF THE DISCHARGE PATTERNS OF POPULATIONS OF AUDITORY-NERVE FIBERS
REPRESENTATION OF STEADY-STATE VOWELS IN THE TEMPORAL ASPECTS OF THE DISCHARGE PATTERNS OF POPULATIONS OF AUDITORY-NERVE FIBERS
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DOI：
10.1121/1.383532
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发表时间：
1979-01-01
影响因子：
2.4
通讯作者：
SACHS, MB
中科院分区：
文献类型：
--
作者：
YOUNG, ED;SACHS, MB
本文研究了合成的稳态元音的频谱在听觉神经纤维放电时间方面的表现。本文研究了麻醉猫大量单根交感神经纤维的反应。通过对每只猫遇到的所有纤维提供相同的刺激，可以估计对这些刺激的群体反应。构建了每个单元对元音反应的周期直方图。纤维对刺激的每个谐波分量的时间响应被认为是单位周期直方图的傅里叶变换中相应分量的幅度。在低声级下，对每个刺激分量的时间响应在具有接近分量频率的CF [特征频率]的单元中是最大的（即，在其位置附近）。对共振峰成分的响应大于对其他刺激成分的响应。随着声级的增加，对共振峰的响应，特别是第一共振峰，在它们的位置附近增加并扩散到相邻区域，特别是朝向更高的CF。除了共振峰的谐波和互调产物之外，对非共振峰分量的响应被抑制;在所使用的最高声级（约80 dB SPL，声压级）下，时间响应几乎完全发生在前2或3个共振峰及其谐波和互调产物处。描述了一种简单的计算，其结合了速率、位置和时间信息以提供元音频谱的良好表示，包括至少前2个共振峰频率的清楚指示。这种表示在至少高达80 dB SPL的声级变化下是稳定的;它的稳定性与元音频谱表示在放电率方面的行为形成鲜明对比，放电率在人类会话范围内的刺激水平下退化。
The representation of the spectra of synthesized steady-state vowels in the temporal aspects of the discharges of auditory-nerve fibers was studied. The responses of large numbers of single auditory-nerve fibers in anesthetized cats were studied. By presenting the same set of stimuli to all the fibers encountered in each cat, the population response to those stimuli can be estimated. Period histograms of the responses of each unit to the vowels were constructed. The temporal response of a fiber to each harmonic component of the stimulus is taken to be the amplitude of the corresponding component in the Fourier transform of the unit''s period histogram. At low sound levels, the temporal response to each stimulus component is maximal among units with CF [characteristic frequencies] near the frequency of the component (i.e., near its place). Responses to formant components are larger than responses to other stimulus components. As sound level is increased, the responses to the formants, particularly the 1st formant, increase near their places and spread to adjacent regions, particularly toward higher CF. Responses to nonformant components, except for harmonics and intermodulation products of the formants are suppressed; at the highest sound levels used (approximately 80 dB SPL, sound pressure level), temporal responses occur almost exclusively at the first 2 or 3 formants and their harmonics and intermodulation products. A simple calculation was described which combines rate, place and temporal information to provide a good representation of the vowels spectra, including a clear indication of at least the first 2 formant frequencies. This representation is stable with changes in sound level at least up to 80 dB SPL; its stability is in sharp contrast to the behavior of the representation of the vowels'' spectra in terms of discharge rate which degenerates at stimulus levels within the human conversational range.