Chalikia M H, Bregman A S
McGill University, Montreal, Quebec, Canada.
Percept Psychophys. 1993 Feb;53(2):125-33. doi: 10.3758/bf03211722.
This experiment was an investigation of the ability of listeners to identify the constituents of double vowels (pairs of synthetic vowels, presented concurrently and binaurally). Three variables were manipulated: (1) the size of the difference in F0 between the constituents (0, 1/2, and 6 semitones); (2) the frequency relations among the sinusoids making up the constituents: harmonic, shifted (spaced equally in frequency but not integer multiples of the F0), and random; and (3) the relationship between the F0 contours imposed on the constituents: steady state, gliding in parallel, or gliding in opposite directions. It was assumed that, in the case of the gliding contours, the harmonics of each vowel would "trace out" their spectral envelope and potentially improve the definition of the formant locations. It was also assumed that the application of different F0 contours would introduce differences in the direction of harmonic movement (common fate), thus aiding the perceptual segregation of the two vowels. The major findings were the following: (1) For harmonic constituents, a difference in F0 leads to improved identification performance. Neither tracing nor common-fate differences add to the effect of pitch differences. (2) For shifted constituents, a difference between the spacing of the constituents also leads to improved performance. Formant tracing and common fate contribute some further improvement. (3) For random constituents, tracing does not contribute, but common fate does.
本实验旨在研究听众识别双元音（同时双耳呈现的合成元音对）成分的能力。实验操纵了三个变量：（1）成分之间F0的差异大小（0、1/2和6个半音）；（2）构成成分的正弦波之间的频率关系：谐波关系、移位关系（频率等距分布但不是F0的整数倍）和随机关系；（3）施加在成分上的F0轮廓之间的关系：稳态、平行滑动或反向滑动。假定在滑动轮廓的情况下，每个元音的谐波会“描绘出”它们的频谱包络，并可能改善共振峰位置的清晰度。还假定应用不同的F0轮廓会在谐波运动方向上引入差异（共同命运），从而有助于两个元音的感知分离。主要研究结果如下：（1）对于谐波成分，F0差异会提高识别性能。频谱描绘和共同命运差异都不会增加音高差异的效果。（2）对于移位成分，成分间距之间的差异也会提高性能。共振峰描绘和共同命运会带来进一步的改善。（3）对于随机成分，频谱描绘没有作用，但共同命运有作用。
