The evolutionary theory is thus propounded by Romanes in his “Mental Evolution in Man,” pp. 377-399: “Starting from the highly intelligent and social species of anthropoid ape as pictured by Darwin, we can imagine that this animal was accustomed to use its voice freely for the expression of the emotions, uttering danger signals, and singing. Possibly it may also have been sufficiently intelligent to use a few imitative sounds; and certainly sooner or later the receptual life of this social animal must have advanced far enough to have become comparable with that of an infant of about two years of age. That is to say, this animal, although not yet having begun to use articulate signs, must have advanced far enough in the conventional use of natural signs (a sign with a natural origin in tone and gesture, whether spontaneously or intentionally imitative) to have admitted of a totally free exchange of receptual ideas, such as would be concerned in animal wants and even, perhaps, in the simplest forms of co-operative action. Next I think it probable that the advance of receptual intelligence which would have been occasioned by this advance in sign-making would in turn have led to a development of the latter—the two thus acting and reacting on each other until the language of tone and gesture became gradually raised to the level of imperfect pantomime, as in children before they begin to use words. At this stage, however, or even before it, I think very probably vowel sounds must have been employed in tone language, if not also a few consonants. Eventually the action and reaction of receptual intelligence and conventional sign-making must have ended in so far developing the former as to have admitted of the breaking up (or articulation) of vocal sounds, as the only direction in which any improvement in vocal sign-making was possible.” Romanes continues his sketch by referring to the probability that this important stage in the development of speech was greatly assisted by the already existing habit of articulating musical notes, supposing our progenitors to have resembled the gibbons or the chimpanzees in this respect. Darwin in his great work on the “Expression of the Emotions” points to the fact that the gibbon, the most erect and active of the anthropoid apes, is able to sing an octave in half-tones, and it is interesting to note that Dubois considers his Pithecanthropus Erectus is on the same stem as the gibbon. But it has lately been shown that some animals much lower in the scale than monkeys, namely, rodents, are able to produce correct musical tones. Therefore the argument loses force that the progenitors of man probably uttered musical sounds before they had acquired the power of articulate speech, and that consequently, when the voice is used under any strong emotion, it tends to assume through the principle of association a musical character. The work of anthropologists and linguists, especially the former, supports the progressive-evolution theory, which, briefly stated, is—that articulate language is the result of an elaboration in the long procession of ages in which there occurred three stages—the cry, vocalisation, and articulation. The cry is the primordial, pure animal language; it is a simple vocal aspiration without articulation; it is either a reflex expressing needs and emotions, or at a higher stage intentional (to call, warn, menace, etc.). Vocalisation (emission of vowels) is a natural production of the vocal instrument, and does not in itself contain the essential elements of speech. Many animals are capable of vocalisation, and in the child the utterance of vowel sounds is the next stage after the cry.
The conditions necessary to the existence of speech arose with articulation, and it is intelligence that has converted the vocal instrument into the speaking instrument. For whereas correct intonation depends upon the innate musical ear, which is able to control and regulate the tensions of the minute muscles acting upon the vocal cords, it is intelligence which alters and changes the form of the resonator by means of movement of the lips, tongue, and jaw in the production of articulate speech. The simple musical instrument in the production of phonation is bilaterally represented in the brain, but as a speaking instrument it is unilaterally represented in right-handed individuals in the left hemisphere and in left-handed individuals in the right hemisphere. The reason for this we shall consider later; but the fact supports Darwin’s hypothesis.
Another hypothesis which was brought forward by Grieger and supported by some authors is summarised by Ribot as follows: “Words are an imitation of the movements of the mouth. The predominant sense in man is that of sight; man is pre-eminently visual. Prior to the acquisition of speech he communicated with his fellows by the aid of gestures and movement of the mouth and face; he appealed to their eyes. Their facial ‘grimaces,’ fulfilled and elucidated by gesture, became signs for others; they fixed their attention upon them. When articulate sounds came into being, these lent themselves to a more or less conventional language by reason of their acquired importance.” For support of this hypothesis the case of non-educated deaf-mutes is cited. They invent articulate sounds which they cannot hear and use them to designate certain things. Moreover, they employ gesture language—a language which is universally understood.
Another theory of the origin of the speaking voice is that speech is an instinct not evolved, but breaking forth spontaneously in man; but even if this be so, it was originally so inadequate and weak that it required support from the gesture language to become intelligible. This mixed language still survives among some of the inferior races of men. Miss Kingsley and Tylor have pointed out that tribes in Africa have to gather round the camp fires at night in order to converse, because their vocabulary is so incomplete that without being reinforced by gesture and pantomime they would be unable to communicate with one another. Gesture is indispensable for giving precision to vocal sounds in many languages, e.g. those of the Tasmanians, Greenlanders, savage tribes of Brazil, and Grebos of Western Africa. In other cases speech is associated with inarticulate sounds. These sounds have been compared to clicking and clapping, and according to Sayce, these clickings and clappings survive as though to show us how man when deprived of speech can fix and transmit his thoughts by certain sounds. These mixed states represent articulate speech in its primordial state; they represent the stage of transition from pure pantomime to articulate speech.
It seems, then, that originally man had two languages at his disposal which he used simultaneously or interchangeably. They supported each other in the intercommunication of ideas, but speech has triumphed because of its greater practical utility. The language of gesture is disadvantageous for the following reasons: (1) it monopolises the use of the hands; (2) it has the disadvantage that it does not carry any distance; (3) it is useless in the dark; (4) it is vague in character; (5) it is imitative in nature and permits only of the intercommunication of ideas based upon concrete images. Speech, on the other hand, is transmitted in the dark and with objects intervening; moreover, distance affects its transmission much less. The images of auditory and visual symbols in the growth of speech replace in our minds concrete images and they permit of abstract thought. It is dependent primarily upon the ear, an organ of exquisite feeling, whose sensations are infinite in number and in kind. This sensory receptor with its cerebral perceptor has in the long process of time, aided by vision, under the influence of natural laws of the survival of the fittest, educated and developed an instrument of simple construction (primarily adapted only for the vegetative functions of life and simple vocalisation) into that wonderful instrument the human voice; but by that development, borrowing the words of Huxley, “man has slowly accumulated and organised the experience which is almost wholly lost with the cessation of every individual life in other animals; so that now he stands raised as upon a mountain-top, far above the level of his humble fellows, and transfigured from his grosser nature by reflecting here and there a ray from the infinite source of truth.” Thought in all the higher mental processes could not be carried on at all without the aid of language.
Written language probably originated in an analytical process analogous to the language of gesture. Like that, it: (1) isolates terms; (2) arranges them in a certain order; (3) translates thoughts in a crude and somewhat vague form. A curious example of this may be found in Max Müller’s “Chips from a German Workshop,” XIV.: “The aborigines of the Caroline Islands sent a letter to a Spanish captain as follows: A man with extended arms, sign of greeting; below to the left, the objects they have to barter—five big shells, seven little ones, three others of different forms; to the right, drawing of the objects they wanted in exchange—three large fish-hooks, four small ones, two axes, two pieces of iron.”
Language of graphic signs and spoken language have progressed together, and simultaneously supported each other in the development of the higher mental faculties that differentiate the savage from the brute and the civilised human being from the savage. In spoken language, at any rate, it is not the vocal instrument that has been changed, but the organ of mind with its innate and invisible molecular potentialities, the result of racial and ancestral experiences in past ages. Completely developed languages when studied from the point of view of their evolution are stamped with the print of an unconscious labour that has been fashioning them for centuries. A little consideration and reflection upon words which have been coined in our own time shows that language offers an abstract and brief chronicle of social psychology.
Articulate language has converted the vocal instrument into the chief agent of the will, but the brain in the process of time has developed by the movements of the lips, tongue, jaw, and soft palate a kinæsthetic¹ sense of articulate speech, which has been integrated and associated in the mind with rhythmical modulated sounds conveyed to the brain by the auditory nerves. There has thus been a reciprocal simultaneity in the development of these two senses by which the mental ideas of spoken words are memorised and recalled. Had man been limited to articulate speech he could not have made the immense progress he has made in the development of complex mental processes, for language, by using written verbal symbols, has allowed, not merely the transmission of thought from one individual to another, but the thoughts of the world, past and present, are in a certain measure at the disposal of every individual. With this introduction to the subject I will pass on to give a detailed description of the instrument of the voice.