Oliver Wendell Holmes

The human language is different from the other species. While other animal communication systems is designed to meet their basic needs—which are necessary to develop survival strategies so that they can play their role in the ecosystem—the human language has many additional facets which are absent in animals. We tell stories, share ideas, exchange information, explain how to repair a flat tire, give advice, ask the meaning of life, teach physics, tell a lie and so on. There are good reasons for believing that a special relationship exists between human language and what makes the human brain different from other mammals. (1)

How do people acquire language? What was the first language spoken on earth? These and many other questions have occupied the minds of people for centuries. Hence, language-related experiments date back to ancient times. The earliest experiments were a type of language deprivation experiments in which infants were isolated from their society to prevent any possible language contact. The experiment usually lasted two years when the babbling stage was over. The first known experiment, which is also cited as the first instance of using the experimental method in the study of social phenomena, took place in Egypt. Pharaoh Psammetichus believed that Egyptians were the most ancient race. In order to prove his hypothesis, he ordered two infants to be brought up by a mute shepherd. He was curious to know which word the children would articulate first. After two years, the children spoke the word becos which meant “bread” in Phrygian. He admitted that Phrygians preceded them in antiquity. (2) A more recent experiment took place in India in the sixteenth century. Sultan Akbar believed that people learnt to speak by listening to one another. He ordered two infants and a mute nurse to be placed in one house. At the end of the experiment, the babies failed to develop any language. This proved the validity of his hypothesis. He was not the first to establish a link between language and society. Ibn Sina (Avicenna) proposed that language was innate, that infants were born with the ability to speak, and that language learning can take place in a society. (3) Rumi mentions a story about an infant in his Mathnawi. A female tiger takes care of the infant. When the child reaches age two, a fairy comes and teaches language and manners. The tale in Mathnawi indicates that the socio-cognitive aspect of language was well-known by the people who lived centuries ago, and not a new phenomenon established by contemporary linguists.

The above historical examples are related to the cognitive and social aspect of the language.When we say that language is unique to humans, the first thing that comes to mind is the cognitive aspect of language. However, the uniqueness of language is not merely confined to cognition. There are other features of language which can be considered unique to humans. Anatomical, neurological and physiological aspects make human language unique. This paper will focus on the anatomy of speech organs and more importantly on the vocal tract.

Lungs, larynx, tongue, teeth, and lips make up the major speech organs of the body. Location of the spinal cord also has a contribution to speech. The enlarged region of the spinal cord is responsible for the voluntary control of breathing required by speech production. (4) There is a delicate design in the order of the speech organs in the human anatomy. They operate in such a harmonious way that any mismatch or anatomical deformation of these organs will have a serious effect on speech production. Therefore, the anatomical order of speech organs has a great role in their functionality. If the larynx were located above its present location in the throat, it would restrict vocalization and would not be useful for speech. Although humans share speech organs with primates, just like it shares many other organs, no primate can come up with language. Primates do not possess enough cognitive abilities to speak like a human being. In fact, cognition is one aspect of the issue as mentioned above. However, there is another thing that needs to be taken into consideration and that is the anatomy of the vocal tract which is different in both humans and primates. In order to produce human-like speech, a human-like vocal tract is needed.

The human vocal tract is unique to humans. The vocal tract can be viewed as an acoustic tube extending from the larynx to the lips. It is the main source of the resonances responsible for shaping the spectral envelope of the speech signal. The shape of the vocal tract (or more accurately its area of function) at any point in time is the most important determinant of the speech frequencies of the (oral) cavity. (5) The vocal tract can be divided into two parts: Supralaryngeal Vocal Tract in the vertical dimension and Supralaryngeal Vocal Tract in the horizontal dimension. SVTh includes the oral cavity while SVTv includes the throat, pharynx, behind the tongue and above the larynx. Interestingly, these two vertical and horizontal vocal tracts form a right angle. They are approximately equal in length giving them a 1:1 proportion. The length and the shape of the vocal tract is highly important in the formation of speech. (6) Vowels like [i], [u] and [a] can only be produced with the current anatomy of the human vocal tract. These letters exist in almost all languages.

Cognitive scientist Philip Lieberman stated that the primate vocal tract is different from the adult human’s. Humans have a 1:1 ratio of vocal tract in the horizontal and vertical dimension. However, primates have longer proportion in the horizontal dimension. They have a relatively smaller tongue and oral cavity. The anatomical restrictions do not allow them to produce [i], [u] and [a] vowels. However, in the first half of the twentieth century, linguists spent great efforts to train apes to speak like a human being. After hours of laboratory training, some apes managed to learn a few words. They uttered these words with a raspy pronunciation. Basically, the human language experience of apes did not last long. The vocal tract of chimps may not provide the articulators with enough degrees of freedom to articulate human speech sounds. (8)

The position of the larynx is highly critical. The change in the position of the larynx allows us to independently vary the area of the oral and pharyngeal tubes and to create a broad variety of vocal tract shapes and formant patterns, thus expanding our phonetic repertoire. (5) Human larynx is simpler in structure than that of other primates. This is another advantage on the human side since air can move freely through the nose and the mouth without being stopped by other appendages. The other major anatomical difference between man and primate is the fact that human beings have descended larynxes whereas the primates have their larynx situated above the throat. Human infants also share a similar vocal tract distribution with primates. This position of the larynx serves a vital function for the infant. The larynx works like a seal blocking the nasal cavity. The infant can breathe while he or she is enjoying the mother’s milk. The milk goes directly to the esophagus through the mouth. The air goes to the trachea through the nasal cavity and the larynx. This anatomical structure allows the infant to suckle and breathe at the same time.

Speech organs inside the oral cavity such as tongue and teeth have great contribution in the formation of the speech. In her book, The Articulate Mammal, Jean Aitchison explains how human teeth are unusual compared to those of animals:

“They are even in height, and form an unbroken barrier. They are upright, not slanting outwards, and the top and bottom set meet. Such regularity is surprising – it is certainly not needed for eating. Yet evenly spaced, equal-sized teeth which touch one another are valuable for the articulation of a number of sounds, S, F, and V, for example, as well as SH (as in shut), TH (as in thin) and several others. Human lips have muscles which are considerably more developed and show more intricate interlacing than those in the lips of other primates. The mouth is relatively small, and can be opened and shut rapidly. This makes it simple to pronounce sounds such as P and B, which require a total stoppage of the airstream with the lips, followed by a sudden release of pressure as the mouth is opened. The human tongue is thick, muscular and mobile, as opposed to the long, thin tongues of monkeys. The advantage of a thick tongue is that the size of the mouth cavity can be varied allowing a range of vowels to be pronounced. It seems, then, that humans are naturally geared to produce a number of different sounds rapidly and in a controlled manner.” (10)

In the light of comparative anatomy, it has become clear that every possible configuration is made at an anatomical level to make humans speak. The design of the vocal tract and the position of the speech organs tell us that the Creator wished for humans to speak:“(Having brought him into existence, God) taught Adam the names, all of them. Then (in order to clarify the supremacy of humankind and the wisdom in their being created and made vicegerent on the earth), He presented them (the things and beings, whose names had been taught to Adam, with their names) to the angels, and said, “Now tell Me the names of these” (Al-Baqarah, 2:31).

In a nutshell, human beings without language would serve no purpose in the universe. In order to read and understand what the Creator wants from them, language serves as a means of communication between human beings and their Creator.

Seyfi Agirel is a PhD candidate in Linguistics at Hacettepe University, Ankara. He is also a lecturer at Turgut Ozal University.

References

1. Ingram, C.L., John, 2007. Neurolinguistics: An Introduction to Spoken Language Processing and Its Disorders, Cambridge University Press.

2. Sulek, Antoni. 1989. “The Experiment of Psammetichus: Fact, Fiction, and Model to Follow,” Journal of the History of Ideas, Vol. 50, No. 4 (Oct. - Dec.), pp. 645-651.

3. Demir, Ramazan. 2008. The Issue of the Source of Languages according to the Arab Linguists. Unpublished PhD thesis, Istanbul: Marmara University.

4. Pinker, Steven, Jackendoff, Ray. 2005. “The Faculty of Language: What’s Special about it?” Cognition, 95, pp. 201-236.

5. Hauser, D. Marc, Fitch, W. Tecumseh. 2003. “What Are the Uniquely Human Components of the Language Faculty?” In Language Evolution, by Christiansen, Morten H. and Kirby, Simon, first ed., New York: Oxford University Press.

6. Liebermann, Philip, McCharty, Robert. 2007. “Tracking the Evolution of Language and Speech,” Expedition, Vol. 49. No. 2, pp. 15-20.

7. Pollick, S. Amy, De Waal, B.M. Frans. 2007. “Ape Gestures and Language Evolution,” Proceedings of the National Academy of Sciences of the United States, Vol. 104. No. 19, May 8, pp. 8184-8189.

8. Weiss, J. Daniel, Newport, Elisa. 2006. “Mechanisms Underlying Language Acquisition: Benefits From a Comparative Approach,” Infancy, Vol. 9, No. 2, pp. 241-257.

9. Aitchison, Jean. 2008. The Articulate Mammal, Fifth ed. New York: Routledge.