Lieberman P H, Klatt D H, Wilson W H
Science. 1969 Jun 6;164(3884):1185-7. doi: 10.1126/science.164.3884.1185.
The vowel repertoire of a rhesus monkey (Macaca mulatta) was explored by means of a computer program that calculated formant frequencies from the area function of the animal's supralaryngeal vocal tract, which was systematically varied within the limits imposed by anatomical constraints. The resulting vowels were compared with those of humans and with recorded vocalizations of nonhuman primates. The computer model indicates that the acoustic "vowel space" of a rhesus monkey is quite restricted compared to that of the human. This limitation results from the lack of a pharyngeal region that can change its cross-sectional area. These animals thus lack the output mechanism necessary for production of human speech. Man's speech output mechanism is apparently species-specific.
通过一个计算机程序对恒河猴（猕猴）的元音系统进行了探究，该程序根据动物喉上声道的面积函数计算共振峰频率，喉上声道在解剖学限制所规定的范围内系统地变化。将得到的元音与人类的元音以及非人类灵长类动物的录音发声进行了比较。计算机模型表明，与人类相比，恒河猴的声学“元音空间”相当有限。这种限制是由于缺乏一个可以改变其横截面积的咽部区域。因此，这些动物缺乏产生人类语音所需的输出机制。人类的语音输出机制显然是物种特有的。
