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.