If, then, we speak without consciousness of the separate sounds, much more are we completely unconscious of the movements of our vocal organs. It is only very recently that these movements have been carefully investigated, and the results of the science of phonetics are in very many respects as yet sub judice, while even the most superficial knowledge of the subject can only be attained by a conscious and careful effort of attention, and by the exercise of much patience in the observation of our precise actions when speaking. It is only the trained observer who can at all follow these movements as he makes them, and even he does not so follow them generally, but thinks of the sense of his words as he speaks, and not of the way in which they are produced.
Moreover, even assuming that the speaker enjoyed a far higher degree of consciousness, both of phonetic elements and of phonetic movement while he is acquiring the faculty of speech, it would none the less remain true that in the ordinary course of word-utterance these facts remain outside the speaker’s consciousness. A precisely parallel instance can be observed in the case of a pupil learning to play the piano or violin. At first every movement he makes is the result of a separate and conscious act of volition; but soon practice, the repetition of conscious action, so much facilitates the playing of scales, arpeggios, etc., that the rapidity of their execution quite precludes all possibility of the bestowal of separate thought, even of the shortest duration, upon each individual note in succession. It is necessary at the outset to insist on this fact of the speaker’s unconsciousness, both of the elements of sound which make up the word, and of the movements of his vocal organs; for, once fully grasped, it will guard against an error which is too prevalent, viz. that sound-change is the result of conscious volition in those who speak.
But though the movements necessary for production of sounds are performed unconsciously, they are by no means beyond control; to illustrate which fact we may once more recur to the parallel instance of the piano-player. Like him, the speaker controls his work by listening to its result: but the player strikes either the right note or the wrong, and, unlike him, the speaker may vary his utterance in one direction or another without serious error; he is not considered to make a MISTAKE unless the difference between his present utterance and that which is usual exceeds a certain limit. In this respect, the violin-player resembles the speaker more closely. They both appeal to their sense of hearing in order to decide on the correctness or otherwise of the sound produced, and the control they can exercise over that sound is exactly proportional to their delicacy of ear. Up to certain limits, the variations are too small to be perceived by the ear, but beyond these, control becomes possible. The slight differences in pronunciation or sound do not yet, however, necessarily expose the speaker (or player) to the charge of incorrect utterance (or performance), and consequently, though he perceives the change, he pays little or no attention to it. He only then corrects himself or guards against repeating the ‘mistake,’ when the change in sound passes those limits which cannot be transgressed without detriment to what in music we term ‘harmony,’ or what in language we term ‘correctness of utterance.’ It commonly happens that these limits are wider than the limits of perception referred to above, more especially in the case of the speaker. A wider licence is accorded to the term ‘correctness’ in speech than is accorded to it in harmony.
While, then, control is theoretically and practically limited, the possibility of variation is unlimited. Take, for instance, the case of the vowels. All the possible sounds and variations from u (pronounced as oo in cool) to i (= ee in feel) may be said to form one uninterrupted series. In this series we distinguish only some of the most important varieties. When we pronounce u, the lips are rounded, and the tongue is drawn back and raised at the back of the mouth: if we pass from u to i, the lips are unrounded, and assume the shape of a narrow and much elongated ellipse, while the tongue is pushed forward with its back depressed and the fore-part (the blade) raised. While this change is going on, the mouth never assumes a position with which we could not produce some vowel or other, but the difference in acoustic quality between any two ‘neighbouring’ vowels would not always be such that we should regard them as distinct or different sounds. On our way from u to i, we pass through the positions for the o (oa) in coal, the ŏ in god, the a in father, the ĕ in net, the e (a) in hare, the ĭ in pit; but between these there lie an indefinite number of possible shades of sound, and every one knows how differently various speakers of the same community pronounce what we call the same vowel. So, too, we need but little attention to notice distinct occasional variations, at different moments, in the same speaker. If, then, one and the same speaker often perceptibly (though unintentionally) varies his pronunciation, we may be perfectly sure that his mode of utterance will vary at different times within those limits where the divergence—though existing—is not noticed. As with the vowels, so it is, though not so completely, with many consonants and series of consonants. The student who is unacquainted with phonetics should pronounce cool and keen one after the other, or better still coo and kee, getting rid of the final consonants. He will have no difficulty in noticing the difference between the two k sounds, the first of which requires a much more backward position than the second for its pronunciation. After a little practice, he will be able to pronounce the first (back) k with the ee vowel, and the second (forward, palatal) k with oo. Now, between these two sounds of k there is a whole series of intermediate ones, and, if this series be followed in the direction of the palatal k and then continued beyond it, we soon reach the articulation of the palatals proper, and pass, without any appreciable gap, to the linguo-dentals: first to the t which, in words like the French métier, sounds so much like q in the form méquier (as the French Canadians actually pronounce it); and next to our own t, and to the usual French t, which is pronounced more to the front with the tip of the tongue against the roots of the teeth.
Similarly, because perfect though slight closure is not remote from extreme narrowing, we can pass in a practically unbroken series from energetic p to laxly uttered f, from k to the guttural fricative of German ach—a sound which English, in its modern form, no longer possesses,—etc.
As we noticed in the instance of k, and as every one more easily perceives in the case of the vowels, two sounds essentially different in articulation and in acoustic character are often, in daily speech, accepted as identical, more especially where the difference is not great enough, or is not of a nature to cause ambiguity of meaning. If, for instance, there existed words in the English language alike in all respects but that the one began with the k of cool and the other with the k of keen, and if these words had different meanings, every Englishman would be aware of the existence of two sounds, which he would most likely indicate by two different letter-signs. As it is, the difference between the two remains unnoticed, and the choice between them depends upon the vowel which follows. If, then, in the ordinary course of speaking, a ‘back’ k is pronounced a little more forward, or a palatal k more to the back, no notice will be taken of it, unless the variation oversteps a certain limit and, as a consequence, the unusual articulation sounds strange. Similarly, for the formation of t, the position of the tongue may be varied to a very great extent, and yet, though something unusual in the sound MAY be apprehended, the result will always be perceived as a t.
We must now once more emphasise the fact that the memory-picture of the sound, and the (unconscious) memory-picture of the movement and position, and these two alone, connect the various utterances of any sound or sound-group, and decide its character, and the appreciation of speaker and hearer to its correctness.
These memory-pictures and their nature and growth are therefore of the highest importance. They are the results of all preceding cases of utterance, of which, however, the last always has the greatest influence. Every variation in pronunciation entails a variation in the memory-picture; and this, small as may be the change, is cumulative and permanent, unless the different deviations happen to balance one another exactly. Now, in the main this will be the case when the speaker finds himself amid his usual surroundings, and where no external causes co-operate to impel his deviations into one direction rather than into another: but let us suppose him transferred to another community, and brought in contact with a certain pronunciation habitual there and novel to him. His memory-picture of the SOUND is made up of his own pronunciation and of what he hears from others. At first the new pronunciation strikes him as new, and two pictures stand side by side in his mind. If, however, the difference be not too great, these soon blend, and, the former one fading while the other constantly gains in force, his pronunciation becomes influenced without his own knowledge; he pronounces more and more like the surrounding speakers, and every time he does so his memory-picture of POSITION gets slightly altered (always in the same direction) until nothing but conscious effort of memory or renewed intercourse with former surroundings can recall the one thus lost.
The same thing happens essentially and effectually, though the change is slower and less violent, where external causes favour deviation in any special direction amongst an entire community. As far as the nature of the effect goes, it can make no difference whether we consider the case of a man entering a new community to find there a pronunciation which differs from his own, or that of an entire community which alters its existing pronunciation. But the process will go on much more slowly in the latter case, since it has to operate in a number of individuals, and the steps by which each of them proceeds are in ordinary cases imperceptibly small.
Of all causes which may tend to alter our pronunciation in any special direction, facility of utterance is the most conspicuous and the most easily understood. There are, in all probability indeed, several others: climate, habits of diet, etc., all seem to have some effect, but no one has as yet been able to explain how they operate. Even ease of pronunciation is not yet thoroughly understood in all its bearings. We must not forget that ease is something essentially subjective, and that the memory-pictures of movement and sound and the attempt at correct reproduction of the usual movement and sound are the main factors, while the striving after facility of utterance is a very subordinate one.