The Extent of my Experiments--Apes and Baboons--Miscellaneous
Records of Sound--The Vocal Index.
In quest of the great secret of speech, I have pursued my investigations
chiefly in the direction of learning one tongue, but incidentally I have
made many detours, and I have recorded the sounds of many other forms of
the animal kingdom, besides primates. I have examined the phonation of
lions, tigers, leopards, cats, dogs, birds of many kinds, and the human
voice in speech, music, and laughter. Besides these, I have examined
various musical sounds, especially of the pipe and whistle kinds.
More than a year ago I made some splendid records of the sounds of the
two chimpanzees in the Cincinnati collection. I have not had the
opportunity to study these apes themselves, as I desired to do, since
they are kept so closely confined in a glass house, and for ever under
the eye of their keeper, which conditions are not favourable to the best
results. I am not prepared therefore to give much detail concerning
their speech; but from a careful study of one cylinder containing a
record of their sounds, I was able to discern as many as seven different
phones, all of which come within the scope of the human vocal organs. I
learned one of these sounds, and on a subsequent visit to Cincinnati I
succeeded in attracting the attention of the female, and eliciting from
her a response. She would come to the lattice door of the inner cage by
which I was standing, and when I would utter the sound she would press
her face against the door of the cage and answer it with a like sound.
The male, however, did not appear to notice it with any degree of
concern. I have no idea what the sound meant, and my opportunities have
not been such that I could translate it with the remotest degree of
certainty. [Sidenote: STUDIES IN TROPICAL AFRICA] These apes will be one
of the chief objects of my studies in tropical Africa, as I believe them
to possess a higher type of speech even than the gorilla. In this
opinion, which I reached from the study of other sounds and the types of
skull to which they belonged, I am not alone: Mr. Paul Du Chaillu, Mr.
E. J. Glave, and others who have seen both of these apes in their native
habitat, agree with me on this point. I am aware that this view is not
in strict accord with that of Professor Huxley, who assigns the gorilla
the highest place next to man in the order of Nature, and the chimpanzee
next below him. I shall not here attempt to discuss the question with so
high an authority, and I must confess that the vocal index is not yet so
well defined that it may be relied upon in classifying apes. One aim I
have in view is to study the gorilla and chimpanzee side by side in
their native wilds, and to record, if possible, the sounds of their
voices in a wild state. From the study of the sounds I have made, I feel
confident that all the vocal sounds made by these apes may be uttered by
the human vocal organs.
Some months ago I made a record of the voice of the great Anubis baboon,
in Philadelphia. I did not expect to find in him an elevated type of
speech; but my purpose was to compare it with other Simian sounds, to
see if I could not establish a series of steps in the quality of vocal
sounds which would coincide with certain other characters. I had found
by the study of certain cranial forms that certain vocal types conformed
to certain skulls, and were as much a conformation thereof as are the
cerebral hemispheres. I then believed, and have had no cause since to
recede from it, that the vocal powers were correctly measured by the
gnathic index; that the mind and voice were commensurate; and that as
the cranio-facial angle widens the voice degrades in quality and scope.
In man, I find the highest vocal type, and just as we descend in the
cranial scale, the vocal type descends into sounds less flexible, less
capable, and less musical. These deductions apply only to mammals; among
birds, insects, &c., a different order may prevail.
[Sidenote: RECORDS OF LIONS]
The records of the lions show some strange features in the construction
of sound; and when analysed on the phonograph present some novel
effects. The sound as a whole appears to be broken into broad waves or
pulsations; but on analysing it the fundamental tones somewhat resemble
the sounds produced by drawing a mallet rapidly across the keyboard of a
xylophone, and are characterised by a peculiar resonance something like
the tremulous vibrations of a thin glass containing a small quantity of
water. Each of these separate fundamental sounds, or sound units as they
appear to be, can be further reduced to still smaller vibrations; and
the result suggests that the fundamental sounds themselves are an
aggregation of smaller vibrations. I have not as yet been able to
compare the notes one by one with the scale of the xylophone in order to
ascertain whether or not they obey the laws of sound upon which is
founded the chromatic scale of music. The lion makes only a small number
of different sounds, nearly of the same pitch. I have not analysed the
vocal sounds of the other felines to ascertain to what extent they
coincide with those of the lion; but his appear to be somewhat unlike
any other sounds which I have examined.
Among the few sounds of birds which I have analysed, I may mention the
Trumpeter Crane. I have made one record of this bird which was
sufficiently loud to enable me to obtain some idea of the character of
the sound. I am in doubt as to what the real mode of producing this
sound is. The volume of sound evidently comes from the mouth of the
bird; but while in the act of making it, he appears to bring the whole
body into use, even the feathers appear to take some part in its
production, and the whole frame of the bird vibrates in the act. The
record which I have shows some resemblance, on analysis, to the sound
made by the lion; but it is not sufficiently strong to admit of
analysing the sound units or fundamental sounds.
[Sidenote: DIFFERENCE IN PHONES OF GENERA]
From the many sounds that I have analysed, it appears to me that there
is a difference in the phones of all different genera, and that the
phonetic basis of human speech more closely resembles that of the Simian
than any other sounds; but I wish to be understood distinctly not to
offer this in evidence to establish any physical, mental, or phonetic
affinity between mankind and Simians. I merely state the facts from
which all theorists may deduce their own conclusions.