Post by Pahu79 on Mar 7, 2013 10:30:43 GMT -5
Speech
Speech is uniquely human (a). Humans have both a “prewired” brain capable of learning and conveying abstract ideas, and the physical anatomy (mouth, throat, tongue, larynx, etc.) to produce a wide range of sounds. Only a few animals can approximate some human sounds.
Because the human larynx is low in the neck, a long air column lies above the vocal cords. This helps make vowel sounds. Apes cannot make clear vowel sounds, because they lack this long air column. The back of the human tongue, extending deep into the neck, modulates the airflow to produce consonant sounds. Apes have flat, horizontal tongues, incapable of making consonant sounds (b).
Even if an ape could evolve all the physical equipment for speech, that equipment would be useless without a “prewired” brain for learning language skills, especially grammar and vocabulary.
a. Mark P. Cosgrove, The Amazing Body Human (Grand Rapids: Baker Book House, 1987), pp. 106–109.
“If we are honest, we will face the facts and admit that we can find no evolutionary development to explain our unique speech center[/i] [in the human brain].” Ibid., p. 164.
b. Jeffrey T. Laitman, “The Anatomy of Human Speech,” Natural History, Vol. 93, August 1984, pp. 20–26.
“Chimpanzees communicate with each other by making vocal sounds just as most mammals do, but they don’t have the capacity for true language, either verbally or by using signs and symbols. ... Therefore, the speech sound production ability of a chimpanzee vocal tract is extremely limited, because it lacks the ability to produce the segmental contrast of consonants and vowels in a series....I conclude that all of the foregoing basic structural and functional deficiencies of the chimpanzee vocal tract, which interfere or limit the production of speech sounds, also pertain to all of the other nonhuman primates.” [/i]Edmund S. Crelin, The Human Vocal Tract (New York: Vantage Press, 1987), p. 83.
[From “In the Beginning” by Walt Brown]