Darwin C J
J Acoust Soc Am. 1984 Dec;76(6):1636-47. doi: 10.1121/1.391610.
Speech is normally heard against a background of other sounds, yet our ability to isolate perceptually the speech of a particular talker is poorly understood. The experiments reported here illustrate two different ways in which a listener may decide whether a tone at a harmonic of a vowel's fundamental forms part of the vowel. First, a tone that starts or stops at a different time from a vowel is less likely to be heard as part of that vowel than if it is simultaneous with it; moreover, this effect occurs regardless of whether the tone has been added to a normal vowel, or to a vowel that has already been reduced in energy at the tone's frequency. Second, energy added simultaneously with a vowel, at a harmonic frequency near to the vowel's first formant, may or may not be fully incorporated into the vowel percept, depending on its relation to the first formant: When the additional tone is just below the vowel's first formant frequency, it is less likely to be incorporated than energy that is added at a frequency just above the first formant. Both experiments show that formants may only be estimated after properties of the sound wave have been grouped into different apparent sound sources. The first result illustrates a general auditory mechanism for performing perceptual grouping, while the second result illustrates a mechanism that may use a more specific constraint on vocal-tract transfer functions.
言语通常是在其他声音的背景下被听到的，然而我们在感知上分离特定说话者言语的能力却鲜为人知。此处报告的实验说明了听众判断元音基频谐波处的音调是否构成该元音一部分的两种不同方式。首先，与元音在不同时间开始或结束的音调，比起与元音同时出现的音调，被听作该元音一部分的可能性更小；此外，无论该音调是添加到正常元音上，还是添加到在该音调频率处能量已降低的元音上，这种效应都会出现。其次，在靠近元音第一共振峰的谐波频率处与元音同时添加的能量，可能会也可能不会完全融入元音感知中，这取决于它与第一共振峰的关系：当额外音调刚好低于元音的第一共振峰频率时，比起在刚好高于第一共振峰频率处添加的能量，它被融入的可能性更小。这两个实验都表明，只有在声波特性被分组为不同的明显声源之后，共振峰才可能被估计出来。第一个结果说明了执行感知分组的一般听觉机制，而第二个结果说明了一种可能对声道传递函数使用更特定约束的机制。
