Sinex D G, McDonald L P
Los Alamos National Laboratory, Physiology Group, New Mexico 87545.
J Acoust Soc Am. 1988 May;83(5):1817-27. doi: 10.1121/1.396516.
Responses of chinchilla auditory-nerve fibers to synthesized stop consonants differing in voice onset time (VOT) were obtained. The syllables, heard as /ga/-/ka/ or /da/-/ta/, were similar to those previously used by others in psychophysical experiments with human and with chinchilla subjects. Average discharge rates of neurons tuned to the frequency region near the first formant generally increased at the onset of voicing, for VOTs longer than 20 ms. These rate increases were closely related to spectral amplitude changes associated with the onset of voicing and with the activation of the first formant; as a result, they provided accurate information about VOT. Neurons tuned to frequency regions near the second and third formants did not encode VOT in their average discharge rates. Modulations in the average rates of these neurons reflected spectral variations that were independent of VOT. The results are compared to other measurements of the peripheral encoding of speech sounds and to psychophysical observations suggesting that syllables with large variations in VOT are heard as belonging to one of only two phonemic categories.
获得了灰鼠听觉神经纤维对不同语音起始时间（VOT）的合成塞音的反应。这些音节听起来像/ga/-/ka/或/da/-/ta/，与之前其他人在对人类和灰鼠进行的心理物理学实验中使用的音节相似。对于VOT大于20毫秒的情况，调谐到第一共振峰附近频率区域的神经元的平均放电率通常在发声开始时增加。这些放电率的增加与发声开始时以及第一共振峰激活相关的频谱幅度变化密切相关；因此，它们提供了有关VOT的准确信息。调谐到第二和第三共振峰附近频率区域的神经元在其平均放电率中并未编码VOT。这些神经元平均放电率的调制反映了与VOT无关的频谱变化。将这些结果与语音声音外周编码的其他测量结果以及心理物理学观察结果进行了比较，这些观察结果表明，VOT变化较大的音节被听成仅属于两个音位类别之一。
