Effects of phase and level on vowel identification: data and predictions based on a nonlinear basilar-membrane model.
Effects of phase and level on vowel identification: data and predictions based on a nonlinear basilar-membrane model.
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相位和电平对元音识别的影响：基于非线性基底膜模型的数据和预测。
DOI：
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发表时间：
1996
影响因子：
2.4
通讯作者：
B. Moore
中科院分区：
文献类型：
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作者：
J. Alcantara;I. Holube;B. Moore
本文探讨了元音识别的成分相位和水平的作用，并解释了在非线性基底膜模型的滤波器的输出端发生的波形的形状方面的结果。四个听力正常的受试者被要求识别六个可能的元音样谐波复合体中的哪一个在每次试验中出现。刺激是包含100赫兹基波的前35个谐波的复杂音调。所有低于3000 Hz的谐波的振幅相等，除了三对连续的谐波，在对应于六个元音的前三个共振峰的频率处，其在相对于背景谐波的水平上增加了1、2、4、8和16 dB。谐波复合物中的分量以四种不同的起始相位关系添加;余弦、随机、施罗德正和施罗德负。刺激呈现在三个总体水平; 85，65和45 dB SPL。随机和Schroeder阴性相的性能相似，并且不随水平变化。余弦和Schroeder正相位条件的性能优于其他两个相位条件，但随着水平的降低而降低。所有四个阶段条件的性能与最低水平相当。作为电平和分量相位的函数的性能的变化根据将在非线性"基底膜滤波器"的输出处发生的时间波形的形状来解释[H. W. Strube，J. Acoust.美国社会79，1511 - 1518（1986）]，具有关于中心频率的不对称相位响应。
This paper examines the role of component phase and level on vowel identification and interprets the results in terms of the shapes of the waveforms occurring at the outputs of the filters in a nonlinear basilar-membrane model. Four normally hearing subjects were asked to identify which of six possible vowel-like harmonic complexes was presented on each trial. The stimuli were complex tones containing the first 35 harmonics of a 100-Hz fundamental. All of the harmonics below 3000 Hz were equal in amplitude except for three pairs of successive harmonics, at frequencies corresponding to the first three formants of six vowels, which were incremented in level relative to the background harmonics by 1, 2, 4, 8, and 16 dB. The components in the harmonic complexes were added in four different starting phase relationships; cosine, random, Schroeder positive, and Schroeder negative. The stimuli were presented at three overall levels; 85, 65, and 45 dB SPL. Performance was similar for the random and Schroeder-negative phases and did not vary as a function of level. Performance for the cosine- and Schroeder-positive-phase conditions was better than for the other two phase conditions, but decreased as the level was reduced. Performance for all four phase conditions was equivalent for the lowest level. The variation in performance as a function of level and component phase is explained in terms of the shapes of the temporal waveforms that would occur at the output of nonlinear "basilar-membrane filters" [H. W. Strube, J. Acoust. Soc. Am. 79, 1511-1518 (1986)], with asymmetric phase responses about the center frequency.