Popular Science Monthly/Volume 9/September 1876/Voice in Man and in Animals II


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IN all languages there exist sounds—vowel and consonant—represented by the letters of the alphabet. This, in the opinion of some linguists, is an evidence of a common origin, while naturalists hold it to be the inevitable effect of the functions of an organ whose conformation scarcely differs in any perceptible degree between one race and another. Nevertheless languages differ very much in the number of their intonations. If, in this respect, the languages of uncivilized nations stand lowest, it does-not necessarily follow that the languages of the most highly-civilized peoples must hold the highest rank. The Hindustani is distinguished by an unparalleled abundance of consonants; the Semitic languages surpass the Greek and Latin, as also the languages of modern Europe; the dialects of Polynesia afford instances of the greatest poverty of consonant sounds. Of the Hurons and Mohawks of North America, who habitually kept the mouth open, it is asserted that they knew nothing of the use of the labials—articulations so natural to us that we might be disposed to regard them as instinctive. Sundry nations eschew the use of hissing and trilling sounds;[2] others have no gutturals. Some years ago, preferences for harshness or for softness of language seemed to us to show that neither the vocal organs nor the auditory perceptions are absolutely identical in all races of mankind;[3] this is now rendered more probable by multiplied observations and experiments. We know how great is the difficulty of rendering certain sounds in a foreign language, and hence it is that words change in migrating from place to place. The Chinese invariably substitute the soft for the hard trill,[4] and this substitution is common among other nations. The Polynesians put gutturals in the place of dentals,[5] and the missionaries who are educating the youth of the Hawaiian Islands have had to abandon sounds that the people are unable to pronounce. It is almost as difficult rightly to hear as it is correctly to imitate articulations foreign to one's own tongue: travelers hardly ever agree in their representations of names that they have heard pronounced by natives. Are differences of voice and of auditory perception the result to a small extent of organization, but to a greater extent of early education? One is tempted to believe that such is the case. But experiment and observation, hitherto very limited, have not yet thrown upon this subject the light of scientific truth.

Words are formed by the combination of vowels and consonants; the voice gives utterance to them; this is language which is at first governed by convention, and then by grammar. Pronunciation results from the emission of articulate sounds; its range in pitch is usually about one-half of an octave. Commonly the voice rises or falls a little at the end of a phrase, producing accent, or marking affirmation or interrogation. The adult man, as a rule, speaks in the lower register, children and women in the upper register, but to this there are many exceptions.

Though we all employ speech, yet we differ in ease and agreeableness of utterance. The voice is weak or powerful, as determined by the mode of action of the respiratory organs. The timbre is sharp, harsh, sweet, or harmonious; this is determined by the conformation of the resonant cavities. Whatever quality of voice we happen to have naturally, is to be preserved, though it may be improved by constant attention to the ear, by steady observation, finally by training. Speech does not flow from its source with the same ease in all cases: here the mind is master, and mental qualities differ from one another to a far greater extent than physical aptitudes. Some persons express themselves without difficulty or hesitation—their thinking faculty acts as a continuous force; others seem to grasp a word or a phrase here and there—their thinking faculty is fluctuating, confused, undecided. A certain feeling of constraint produces stuttering, stammering. It used to be supposed that stuttering is the result of grave defects of the vocal organs, but such is not the case at all; this infirmity has its seat in the mind, and it may be cured or mitigated by systematic effort. It is shown by statistics that Provence, Languedoc, and Guienne, contain a greater proportion of stammerers in their population than any other portions of France.[6] This statement, when first I saw it, was a surprise to me; it has always been thought that no one could possibly falter in his speech who was born near the Garonne.[7]

In performing its great function of establishing all the social relations between man and man, the voice readily calls forth sympathies and antipathies; its quality reveals better than words the true feelings of the heart. A voice that is clear, pure, limpid, conveys the impression of frankness; one that is hesitating, drawling, betokens dissimulation; a harsh, grating voice indicates an evil disposition; while a voice that is sweet, harmonious, affects us as though it were the breathing of a gentle soul. These impressions made by the voice are usually correct, and rightly enough influence the relations of man to man, still we must not trust them too implicitly. No doubt language may serve to disguise thought, but the vocal instrument itself may also produce false impressions. Besides the effects of Nature, we have the effects of art. An orator wishing to make himself heard, or to produce a sensation, opens his mouth widely, and derives from the resonant cavities all the aid that they can supply; this is the declamatory style, condensed by good taste. If the mouth be opened very widely, and the breath emitted with force, the voice becomes imperious: such is the tone in which a military officer gives the word of command. Words that are in themselves simple enough, when uttered in a hard, brusque tone, become offensive. When the sounds are uttered softly, with some degree of tremulousness, the words succeeding one another with deliberate slowness and imperceptible lowering of pitch, the sympathy of the hearer is awakened. Some women, it is asserted, possess a wonderful power of thus rendering their entreaties irresistible. Historians affirm that Cicero's graceful utterance added greatly to the persuasive force of his words. The orator who possesses a good voice, and who can at will assume the tones that best agree with the sentiments, emotions, and passions, which he would arouse, will win the hearts of his auditors, whereas the grandest oration delivered by an unpractised speaker would fail to move them.

Singing requires of the vocal organs functions very different from those required for speaking. Furthermore, a good physical constitution and perfect regularity in the functions of the organism, are of inestimable value to the artist. In the emission of the voice the respiratory movements must be performed without strain or effort; they must be so regulated as to make the inspiration short and easy, and the expiration slow and prolonged. There is a struggle between the organs which retain the breath and those which expel it; practice, youth, and good health, are the conditions upon which an adjustment must be based. In the highly-gifted artist the larynx holds its ordinary position notwithstanding the variations of intensity and pitch of the sounds produced. Being implicated in some of the more energetic movements of the tongue, it rises or falls, but to no purpose. The larynx of the singer, while fixed in its position, multiplies its performance; the suppleness of all its parts is a matter of prime importance. The vibrations of the vocal lips and the resonance of the vestibule determine the timbre of the glottic sounds; the configuration of the pharynx and of the buccal cavity, by modifying the sounds formed in the glottis, produces the timbre of the voice. This cannot be altered to any considerable degree by even the most powerful efforts of the will. Professors of singing injure their pupils by prescribing in too absolute a manner the mouth arrangements which they themselves find most serviceable. Each individual must follow Nature, and M. Mandl had good reasons for begging singing-masters never to forget this truth.

Our ear is not affected by all sounds; those which are very low or very acute are not perceived. The limits of hearing are usually set at forty, and at forty thousand vibrations per second. Persons of extreme sensibility are not restricted within these limits, but their gift is not a source of pleasure; every one knows how painful it is to hear sounds that are too acute. Song is the result of modulated sounds separated from one another by harmonic intervals. The whole series of sounds from the grave to the acute is the musical scale; the voice has a greater or less range in different individuals. In the language of musicians, each series of consecutive and homogeneous sounds is a register; we have the chest-register, the head-register, etc. A strange idea has gone abroad: singers, being led astray by the resonance of the arch of the palate, and by certain peculiar sensations caused by the action of various muscles, have supposed that the voice comes now from the chest, again from the head. But, as every one must now be aware, voice is produced always in the glottis. Hence it were well, as M. Mandl advises, to abandon the use of terms which had their origin in a misapprehension, and to use instead of them the terms lower and upper register.

Singing requires far more precise arrangements of the vocal organs than does speaking. At the moment of producing the sound the glottic orifice should be absolutely shut; the voice-emission will be good provided the vocal lips go apart to the proper extent with a kind of suddenness. It is interesting to follow with the eye, by means of the laryngoscope, the play of the instrument in producing successively low and high notes. In producing very low notes the glottic orifice assumes the form of a very long, regular ellipsoid, with both extremities pointed; as the sound rises in pitch, the vocal lips at once approach each other, and the orifice, constricted at one point, appears to be divided into two parts; the pitch still rising, the uttermost limit of the register is attained, and then the glottic orifice becomes a linear slit. Passing to the upper register—the head-voice or falsetto—a curious change takes place suddenly in the configuration of the glottis: it appears to be absolutely shut below and open above. In proportion as the orifice is narrowed, the sound grows higher. The singer recognizes the registers by the ear from the timbre, the physiologist by the eye; for the latter, one of the registers consists of the series of sounds produced by the glottis when open along its entire length, the other register represents the series of sounds given forth by the glottis open through only a limited portion of its orifice.

The ordinary limits of the voice include about two octaves of the musical scale; by practice one can easily attain 2 1/2 octaves, but a compass of three octaves, and especially of 3 1/2 octaves, is very exceptional. Hence, at the beginning of the present century, Catalani was regarded as a sort of prodigy. In classing voices according to pitch we recognize three kinds of voice in men, viz., bass, barytone, and tenor, and three in women, contralto, mezzo-soprano, and soprano. Bass voices rarely fall below 173 vibrations, and soprano seldom exceed 2,069 vibrations per second. Still there have been deep voices which produced the note corresponding to 87 vibrations, and acute voices which attained as many as 2,784. The most famous cantatrices of our day are instances of this.[8] The different types of voice are characterized no less by their timbre than by their range. Voices present so many varieties, they are so personal, that thorough classification is almost impossible. Endless shades of difference are produced by the degree of intensity of the harmonics: if the intensity is great, the voice is brilliant, mordant; if feeble, the voice is soft, sombre. In the larynx itself, and in the trachea, there occurs a resonance, the effects of which have not yet been determined. In bass voices they are very noteworthy. The famous Lablache would have been an excellent subject for experiments by physiologists.

Having ascertained all the functions of the vocal apparatus, and accounted for the origin of the sounds of speech and singing, we may well be proud of the advance made by science, yet we cannot but be chagrined to think that it is not in our power to determine to what peculiarities of organic conformation the different kinds of voice are to be attributed. All that we can affirm with certainty is, that the sound produced is acute in proportion to the shortness of the vocal cords. One might be inclined to believe that the larynx is more voluminous in bassi than in tenori, in contralti than in soprani; but this is not universally the case. We cannot determine either the compass or the quality of a voice from seeing the instrument. The elasticity, suppleness, and contractility of the tissues, must have an immense influence on the glottic sounds, and we possess no means of measuring these qualities.

The character of the voice is fixed from the time when the larynx has reached its full development. So long as the activity of youth continues, the voice will retain this character without any very considerable modification; still, by exercise it will perhaps gain intensity, and may be improved in point of timbre. Suppleness and agility of the organs are acquired only at the cost of labor; this is shown from the history of many a singer. The voice of the young Marie Garcia was at first harsh and husky, but afterward it became the sweet voice of Malibran. Still, as a rule, natural physical gifts manifest themselves prior to any attempt at culture.

As old age approaches, the play of the larynx becomes difficult; at first the tone of the voice is lowered, and then its intensity is lessened; the breath comes with less force. Sometimes disease impairs the instrument before the advent of age. While appearing to be intact, the organ often ceases to discharge its functions perfectly, owing to more or less serious affection of the nervous action. Mandl has, by means of electricity, momentarily restored voices that had been thus destroyed. Songstresses have now and then irretrievably lost their voices in consequence of overstrain of the vocal organs. Here we are reminded of the case of Cornelia Falcon.

Amid the refinements of civilized life, singing is prized only in so far as it is an art; when it rises to that dignity, it attracts crowds. A man or a woman possessing no matter how fine a voice, must begin by going to school. The instrument, whose admirable mechanism we have seen, is not entirely under control, except after much study and long-continued and methodical exercise. This is true of all organs subject to the will, as every one knows from experience, as in the employment of the hands. Though expert in all the movements of the larynx and the mouth, the singer cannot, even with a superb voice, produce brilliant effects, save by the aid of mind. From mind alone come expression, taste, style, and these qualities are all personal. Sensibility, whether real or feigned, is always an element of success. The artist is advised never to give way to the passions which he expresses, for mental commotion is quickly succeeded by extreme fatigue; he may attain a perfect imitation of passions, meanwhile preserving a tranquil mind. Still, are not emotions which are felt always the most communicable?

After we have studied the human voice in its various manifestations, the voice of animals seems to us to be scarcely worthy of notice. The barking of the dog, the mewing of the cat, the bleating of the sheep, undoubtedly constitute a very scanty language. These cries of animals do but annoy us; but it must be remembered that they are intended for other ears than ours. The warbling of small birds alone affords us pleasure; it possesses resemblances which cause pleasing illusions; it seems to express feelings common to ourselves, and hence we like it. The interest attaching to a comparison of the vocal apparatus of animals with that of man has long been appreciated, and the hope has been entertained of being able to explain the nature of all kinds of voice by studying the structure of the organs. Toward the end of the last century, Vicq d'Azyr attacked this problem. Having collected larynges of a number of animals, he regarded them with a sort of enthusiasm; he expected to get from them a revelation. "It is a fine spectacle," said he, "to see at a glance the structure of those infinitely-diversified instruments with which each animal produces its own proper modulations, thus contributing to Nature's grand concert."

The anatomical characters of the vocal apparatus are now pretty well known as regards most of the mammalia. The larynx of these animals is formed upon the same plan as that of man; in monkeys, the resemblance is extreme. The impossibility of speaking is due, as we have reason to suppose, to the conformation of the buccal cavity, the lips, and the tongue. The studies of naturalists, which as yet have not been directed to this point, do not warrant any positive statement: nevertheless, the power possessed by some species of pronouncing one or two syllables justifies a presumption. Does not this vestige of speech indicate the very limited extent of a faculty, not even a trace of which is found in most animals. In 1715 the great Leibnitz announced to our Academy the existence in Meissen of a talking dog, "a peasant's clog, of the most ordinary appearance, and of medium size." This extraordinary animal had learned, says the narrator, some thirty words; these it would repeat after its master. The historian of the Académie des Sciences declares that he would not have ventured to state such a fact "without such an authority as M. Leibnitz, an eye-witness." But, despite so high an authority, the story is a fable. Of the most intelligent dog we still must say, "All he lacks is speech." Were it not that Nature raises an obstacle, surely monkeys that live in the company of man would make the attempt to speak. We must conclude that their intelligence does not incline them toward this sort of imitation, and that their organs are not adapted for articulation.

It is a curious and very interesting fact that, before receiving instruction of any kind, young deaf-mutes who live together quickly discover means of understanding each other, so that they hardly ever misinterpret the feelings and wants expressed by the gesticulations, touches, and facial-muscle action, agreed upon. This instance of a convention between individuals not possessed of the power of employing language of necessity carries our thoughts to the actions of certain animals. The mammalia have a voice that is susceptible of inflexions and intonations more or less diversified according to the species; these they employ in making known to each other their appetites, their wants, to call one another, to announce to one another their presence. It is often said that animals possess only cries, but this statement is too general. The cat says miau, which is a very plain articulation of a labial consonant and three vowels; the word is well formed, and one might suppose it to be Chinese. The cat pronounces this word in many different ways, each having a meaning. If he wants company, he announces his presence in a strong voice; if he wants to be fed, or to have a door opened, his voice is soft and gentle; here is the accent of entreaty. If there is any delay, the tone grows higher, showing impatience. There is a slow, weak miau, which the French translate into "Comme je m'ennuie!" ("How weary I am!") and again there is the wheedling miau, full of pretty modulations, showing plainly a wish to please. Further, the cat says very distinctly ronron, a genuine word formed of trills and nasals; here the tongue and the soft palate perform movements which we know from our own experience. This ronron now means "Thank you;" again, it expresses joy. When moved by a feeling of dislike for an individual of his own race, or of jealousy of a rival, the animal spits and growls, thus giving utterance to threats and imprecations.

The number of mammals which can articulate syllables is small. Sheep utter no sound but that monotonous ba. Some gibbons of the island of Java, when they wish to inspire fear, cry out with fury ra ra. For most animals guttural sounds appear to be uttered with greatest ease. The dog, though highly gifted as regards memory, the sentiment of affection, and intelligence, has no language, but only cries; he barks. Short, sudden expirations of air through the glottis produce this well-known voice; yelping is only a modified form of barking, expressive of joy. Howling is the result of a lengthy expiration with great resonance in the pharynx; it expresses profound grief or pain. Dogs express their wants more frequently by movements of the body, by the play of the physiognomy, and by touching with the muzzle than by the voice. They appear to communicate admirably with one another when organizing an expedition; they inform one another of the presence of objects that gratify their appetite. We once saw in the midst of a meadow, far from any house, the flayed carcass of an ox, which had lain for several days absolutely abandoned. A lonely dog, drawn no doubt by the scent, came to get a meal, and went back to the village to tell his acquaintance of what he had discovered; in less than an hour the carcass was torn in pieces by the teeth of a great troop of dogs.

Opportunities of studying the language of animals in the state of freedom are unfrequent; all animals flee from man, and very wisely. In captivity, and cut off from their own kind, they become silent, or merely utter a few cries or murmurs. Were a human being to be held as a prisoner in a family of chimpanzees he would be reduced to the same extremity. Travelers have sometimes observed monkeys when well within range of sight and hearing; they have always served that the different explosions of voice have each its own meaning, whenever it is designed to establish concert of action between individuals. The cercopitheci, the most graceful and sprightly monkeys of Africa, live together in more or less numerous groups. Having for their usual dwelling-places the branches of trees, they descend to the ground with great misgiving, and only in order to go foraging. On an expedition the band of cercopitheci march under the command of a chief, who is always an old male experienced in the ways of men and animals. At first the troop advance cautiously, passing along the highest branches of the trees. Now and then the chief climbs into one of the loftiest tree-tops and peers into space. If all is well, he makes announcement accordingly in guttural tones, and the troop show that they are reassured; if the chief suspects or perceives danger, he utters a peculiar cry, which is understood by all, and the troop retreat in confusion. The marauders, having reached the edge of the forest, descend to the ground. Then begins a hideous massacre of sorgho and maize. The sajous, those pretty little South American monkeys kept in every menagerie, also show the resources of the inarticulate voice as a means of communication among animals. One day the naturalist Rengger, while wandering along the border of a forest, observed a family of these monkeys whose conduct interested him. One individual, having parted company with the rest, had found an orange-tree loaded with ripe fruit. Without going to the trouble of turning about, he uttered a series of short cries, and made for the tree with the speed of an arrow. The others understood all, and in an instant were assembled amid the branches of the tree, enjoying the savory fruit. If man had no articulate speech, he would have no difficulty in constructing a language by the aid of sounds or cries diversified by intonation, intensity, and resonance, and variously combined. Such a language no doubt could never equal the languages of Homer, of Dante, of Shakespeare, and of Bossuet, but it would answer all the essential needs of life. By supposing such an imaginary though realizable mode of communication, we may form an idea of the more or less limited language of animals.

In mammals the sounds of the voice differ considerably with respect to volume, timbre, and pitch; these differences we can in some measure account for by peculiarities in the conformation of the larynx. In horned animals the vocal cords are lax, but little prominent, never coming near to one another, nor vibrating with much force. The sounds they produce are grave, as in the lowing of cattle. The rodents, as hares, rabbits, squirrels, and mice, whose vocal cords are thin, emit acute cries. Some species, belonging to different mammalian groups, have air-pouches opening into the larynx which produce extraordinary resonance. Some monkeys are distinguished for the enormous development of these pouches, and their voice is very loud. The howling monkeys, also called stentors, which inhabit the deepest forest recesses of the New World, can be heard, says Humboldt, at the distance of a kilometre and a half, and farther still according to other travelers. In the elephant the lateral cartilages of the larynx do not come into mutual contact, and the vocal cords, having an oblique direction, seem to be incapable of great tension; hence the voice of the elephant is deep, but at the same time very powerful. If we could observe in animals the play of the larynx during the emission of the voice, we should discover many curious and instructive actions of the glottis. But here we meet with an almost insuperable difficulty, for we can place but little reliance on the good-will of animals. Nevertheless, Mandl, trusting to his skill in the use of the laryngoscope, by no means despairs of success, knowing well that by dint of patience we often succeed in removing the most formidable obstacles. After man, birds hold the most prominent place among animate things in the concert of Nature; they enliven field, forest, and garden, with an infinity of chirrupings, leading one's thoughts to dwell on the pleasure of living. The structure and mechanism of the vocal apparatus of birds have been studied by many naturalists. George Cuvier discovered the precise point where the voice is formed. Birds have two larynges, one at the top of the trachea, and the other at the bottom. It is the latter alone which produces the sounds: the former acts only as a resonator. This is easily shown by experiment: if we cut the trachea in the middle, the voice remains. The vocal organ has the form of a box, to which anatomists give the name of drum. It is formed of the lowermost rings of the trachea and the uppermost rings of the bronchi. Commonly the larynx is divided in its inferior portion, sometimes by the angle of union of the bronchial tubes, again by a bony plate which serves as a point of attachment for a membrane rising from the inner margin of each of these tubes, and bounding the glottis with an opposing prominence, the edge of which is elastic. Thus two lips discharge the functions of vocal cords; they become tense or relaxed by the action of a muscular apparatus which in some cases is very simple, in others highly complex. The enormous variety which obtains in the vocal powers of birds necessitates a corresponding diversity in the details of the structure of the larynx and in the conformation of the trachea.

Parrots, being social in their nature, live in large flocks in the most favored climates of the globe; their habit of prattling is not impaired by captivity. When several individuals are together, they appear sometimes to engage in interminable conversations. On the alert for every voice-sound, and even for every noise, parrots imitate these with wonderful ease; thus they readily imitate the articulate speech of man, a phenomenon as yet unexplained. The movements of the tongue, no doubt, play an important part in the articulation of these sounds, but the nature of the resonances leads us to suspect a special activity of the superior larynx. The researches which have been undertaken into this matter will perhaps throw some light upon one of the most singular aptitudes possessed by animals. It is commonly supposed that parrots cannot attach any meaning to the phrases which they have learned; but this is not strictly exact. Occasionally individuals possessed of the advantages of great natural intelligence and good training employ words to make requests; they make proper reply to a question or to a sign. It might be supposed that parrots owe their power of speaking to the peculiar conformation of their tongue; but this is rendered doubtful by the performances of the magpie, the blackbird, and the starling. In these birds the tongue is thin, and yet they have no difficulty in pronouncing any articulate sound; this fact gives strength to the idea of the influence of the superior larynx. A starling, distinguished for its power of speaking, which at one time we had occasion to observe, very well knew the value of sundry words. He gave expression to his wants in good French, emphasizing his words with the flapping of his wings. This bird was very fond of the bath, and often called for water; on seeing a person taking hold of a pitcher the bird would exclaim, "Come quick, come quick!" with increasing force in case he was obliged to wait.

Most small birds have their call, their chirp of joy or of fright, their battle-cries: all these voice-explosions, containing as they do both vowel and consonant sounds, show how easy and natural articulation is to these animals. The species which possess the power of singing have a very complex vocal apparatus. The nightingale excels all the other songsters of the woods in power, clearness, and sweetness of tone. Her notes, whether joyous or plaintive, are always melodious. This bird acquires the power of song only after long practice. The young ones are usually very indifferent singers, and it is only those individuals which possess special gifts that give to the vocal art its highest expression. Among all the pretty feathered denizens of our woods, the males alone possess a fine voice; they utter their song in order to win mates who cannot compete in vocal talent. They are mute for a great part of the year, but, when the mating season approaches, their nervous action is quickened, and the blood is determined to the organs of voice.

  1. Translated from the French by J. Fitzgerald, A.M.
  2. f, s, z, l, r.
  3. "Voyage au pôle sud et dans l'Océanie;" "Anthropologie," par M. Émile Blanchard," 1854.
  4. l for r—Eulope for Europe.
  5. gh for d, k for t. This change of pronunciation is not infrequent in some country districts of France.
  6. "Statistique décennale du bégaiement en France," par Chervin âiné, Lyon, 1866.
  7. Memory and the faculty of coördinating words depend upon the brain. It appears, from Broca's researches, that these faculties are destroyed by a lesion of the third frontal convolution of the left side.
  8. In general the bass voice extends from fa1 173 vibrations to re3 580 vibrations; the barytone from la1 217 vibrations to fa3 690; the tenor from re2 290 vibrations to si3 976; the contralto from sol2 387 to fa4 1,381; the mezzo-soprano from si2 488 to la4 1,740; the soprano from ut3 517 to ut5 2,069 vibrations.