CHAPTER XII
The Speech of Chimpanzees—A New System of Phonetic Symbols—Some Common Words—Gestures
The speech of chimpanzees (as of other simians) is limited to a few sounds, and these chiefly relate to their natural wants. The entire vocabulary of their language embraces perhaps not more than twenty-five or thirty words. Many of them are vague or ambiguous, but they express the concept of the ape with as much precision as it is defined to his mind, and quite distinctly enough for his purpose.
During my researches I have learned ten words of the speech of this ape, so that I can understand them and make myself understood by them. In tone, pitch, and modulation most of the sounds are within the compass of the human voice. Two of them are much greater in volume than it is possible for the human lungs to reach, and one of them rises to a pitch more than an octave higher than a human voice of middle pitch. These two sounds are audible at a great distance, but they do not properly fall within the limits of speech.
The vocal organs of the chimpanzee resemble those of man as closely as other physical features have been shown to resemble. They differ slightly in one respect that is worthy of notice. Just above the opening called the glottis (which is the opening between the vocal cords) are two small sacs or ventricles. In the ape these are larger and more flexible than in man. In the act of speaking they are inflated by the air passing out of the lungs into the long tube called the larynx. The function of these ventricles is to control and modify the sound by increasing or decreasing the pressure of the air that is jetted through the tube. They serve at the same time as a reservoir and as a gauge.
In the louder sounds uttered by the chimpanzee these ventricles greatly distend. This intensifies the voice or increases its volume. It is partly due to these little sacs that the ape is able to make such a loud and piercing scream. But the pitch and volume of his voice cannot be alone due to this cause, for the gorilla (in which these ventricles are much smaller) can make a vastly louder sound. We may be mistaken, however, about the sound commonly ascribed to him.
Although the sounds made by the chimpanzee can be imitated by the human voice, they cannot be expressed or represented by any system of phonetic symbols in use among men. Alphabets have been deduced from pictographs, and the conventional symbol that is used to represent a given sound has no reference to the organs of speech that produced it. The few rigid lines that have survived and that now form the alphabets are within themselves meaningless, but they have been so long used to represent the elementary sounds of speech that it would be difficult to supplant them with others.
As no literal formula can be made to represent the phonetic elements of the speech of chimpanzees, I have taken a new step in the art of writing. I suggest a system of symbols which is rational in method and simple in device.
The organs of speech always act in harmony. A certain movement of the lips is always attended by a certain movement of the internal organs of speech. This is true of the ape as well as of man. In order to utter the same sounds, each would employ the same organs and use them in the same manner.
By this means deaf-mutes are able to distinguish the sounds of speech and to reproduce them, although they do not hear them. By close study and long practice they learn to distinguish the most delicate shades of sound.
In this plain fact lies the clue to the method I offer for consideration. As yet it is only in the infant stage, but it is possible to be made, with a very few symbols, to represent the whole range of vocal sounds made by man or other animals.
The chief symbols I employ are the parentheses used in common print. The two curved lines placed with the convex sides opposite, thus, (), represent the open glottis, in which position the voice utters the broad sound of “A,” as in “father.” The glottis about half closed utters the sound of “O.” To represent this sound a period is inserted between the two curved lines, thus, (.). When the aperture is still more contracted it produces the sound of “U,” like “[=oo]” in “woo.” To represent this sound a colon is placed between the lines, thus, (:). When the aperture is restricted to a still smaller compass the sound of “U” short is uttered, as in “but.” To represent this sound an apostrophe is placed between the lines, thus, (.). When the vocal cords are brought to a greater tension, and the aperture is almost closed, it utters the short sound of “E,” as in “met.” To represent this sound a hyphen is inserted between the lines, thus, (-). These are the main vowel sounds of all animals, although in man they are sometimes modified, and to them is added the sound of “E” long, while in the ape the long sounds of “O” and “E” are rarely heard.
From this vowel basis all other sounds may be developed, and by the use of diacritics to indicate the movements of the organs of speech the consonant elements are indicated.
A single parenthesis, with the concave side to the left, will represent the initial sound of “W,” which sometimes occurs in the sounds of animals. When used, it is placed on the left side of the leading symbol, thus,)(), and this symbol, as it stands, is pronounced nearly like “O-A,” the “O” being suppressed until almost inaudible. Turning the concave side to the right, and placing it on the right side of the symbol, thus, ()(, it represents the vanishing sound of “W.” This symbol reads “A-O,” with the latter vocal suppressed into the terminal sound of “O.” The apostrophe placed before or after the symbol will represent “F” or “V.” The grave accent, thus, è, represents the breathing sound of “H,” whether placed before or after the symbol, and the acute accent, thus, é, represents the aspirate sound of that letter.
When the symbol is written with a numeral exponent, it indicates the degree of pitch. If there is no figure, the sound is such as would be made by the human voice in ordinary speech. The letter “X” indicates a repetition of the sound, and the numeral placed after it will show the number of times repeated, instead of the pitch. For example, we will write the sound (.), which is equivalent to long “O,” made in a normal tone; the same symbol written thus (.)2 indicates that the sound is made with greater energy, and about five semitones higher. To write it thus, (.)2X, indicates that the sound is five semitones above the normal pitch of the human voice and is once repeated.
I shall not subject the reader to the tedium of elaborate details of the system here outlined. This brief exposé of the method of representing the sounds of animals is sufficient to convey an idea of the means by which it is possible to write the sounds of all animals, so that the student of phonetics will recognize at once the character of the sound, even if he cannot reproduce it by natural means.
It may be of interest to describe the character and use of some of the sounds uttered by the chimpanzee. The most frequent sound made by animals is that referring to food, and therefore it may claim the first attention. This word in the language of the chimpanzee begins with the short sound of the vowel “U,” which blends into a strong breathing sound of “H.” The lips are compressed at the sides, and the aperture of the mouth is nearly round. It is not difficult to imitate, and the ape readily understands it even when poorly made. By the method of writing above described it is expressed thus, (I)`.
A sound that is of frequent use among them is that used for calling. The vowel element is “[=U]” long, slightly sharpened. It merges into a distinct vanishing “W.” Expressed in symbols, it is (:)(. The food sound is often repeated two or three times in succession, but the call is rarely repeated, except at long intervals.
One sound which is rather soft and musical is an expression of friendship or amity. It appears to soften in tone and lengthen in duration in a degree commensurate with the intensity of the sentiment. The vowel element is a long “U.” It blends into an aspirated “H.” It is fairly represented by the symbol (:)´.
The most complex sound that I have so far heard made by them is the one elsewhere described as meaning “good.” They often use it in very much the same sense as man uses the expression “thanks,” or “thank you.” It is not probable that they use it as a polite term, yet the same idea is present.
One of the words of warning or alarm contains a vowel element closely resembling the short sound of “E.” It terminates with the breathing sound of “H.” It is used to announce the approach of anything that the animal is familiar with, and not afraid of. If the warning is intended to apprise you of the approach of an enemy, or something strange, the same vowel element is used, but terminates with the aspirate sound of “H” pronounced with energy and distinctness. The vowel element is the same in both words, but they differ in the time required to utter them, and the final breathing and aspirate effects. There is also a difference in the manner of the speaker in the act of delivering the word. It plainly indicates that he knows the use and value of the sounds. At the approach of danger the latter word is often given almost in a whisper, and at long intervals apart, increasing in loudness as the danger approaches. The other word is usually spoken distinctly, and frequently repeated. It is worthy of note that the natives use a similar word in the same manner and for the same purpose.
There are other sounds which are easily identified but difficult to describe, such as that used to signify “cold” or “discomfort”; another for “drink” or “thirst,” another referring to “illness,” and still another which I have reason to believe means “dead” or “death.” There are perhaps a dozen more words that can readily be distinguished, but as yet I have not been able to determine their exact meanings. I have an opinion concerning some of them, but have not yet reached a final conclusion about them.
The chimpanzee makes use of a few signs which may be regarded as auxiliary factors of expression. He makes a negative sign by moving the head from side to side in the same manner as man does, but the gesture is not frequent or pronounced. Another negative sign, which is more common, is a wave-like motion of the hand from the body towards the person or thing addressed. This sign is sometimes made with great emphasis. There is no question as to its meaning. The manner of making this sign is not uniform. Sometimes it is done by an urgent motion of the hand. Bringing it from his opposite side, with the back forward, it is thrust towards the person or thing approaching. The interpretation is, that the ape objects to the approach. The same sign is often made as a refusal of anything offered him. Another way of making this sign is with the arm extended forward, the hand hanging down, and the back towards the person approaching or the thing refused. In addition to these negative signs there is one which may be regarded as affirmative. It is made simply by extending one arm towards the person or thing desired. It sometimes serves the purpose of beckoning. In this act there is no motion of the hand. These signs appear to be innate, and are very similar in character to those used by men to signify the same idea.
It must not be inferred from this small list of words and signs that there is nothing left to learn. So far only the first step, as it were, has been taken in the study of the speech of apes. As we grow more familiar with their sounds, the difficulty of understanding them becomes correspondingly less. I have not been disappointed in what I hoped to learn from these animals. The total number of words that I have been able to distinguish up to this time is about one hundred. Of these I have interpreted about thirty. Of late I have given no attention to the small monkeys. I shall resume the study of them at some future day, as it forms an essential part of the task which I have assumed. The fact that animals are able to interpret human speech is of itself proof that they possess the speech instinct. But a careful study of their habits reveals the further proof that they possess and exercise the faculty of speech. In addition to these facts they sometimes acquire new speech sounds. This is progress. If an ape can take one step in the development of speech, why may he not take two? One instance which is cited in the chapter treating of Moses, my ape companion, I regard as the climax of all my efforts in the study or training of apes, and that is the fact that I succeeded in teaching him one word of human speech. This alone is sufficient to demonstrate that the animal has within him the resources of speech.
In conclusion I again assert that the sounds uttered by these apes have the characteristics of human speech. The speaker is conscious of the meaning of the sound used. The pitch and volume of the voice are regulated to suit the condition under which it is used. The ape knows the value of sound as a medium of conveying thought. These and many other facts show that their sounds are truly speech.
To compare the mental faculties of the wild ape to the domesticated dog is not a fair standard by which to measure their respective abilities. The dog has acquired much by his long and intimate association with man. If the ape were placed under domestication, and kept there as long as the dog has been, he would be as far superior to the dog in point of sagacity as he is by nature above the wild progenitors of the canine race.