ve details, which are of little or no
specific interest for us, merely in order to provide something of an
experimental basis to convince ourselves of the tremendous variability
of speech sounds. Yet a complete inventory of the acoustic resources of
all the European languages, the languages nearer home, while
unexpectedly large, would still fall far short of conveying a just idea
of the true range of human articulation. In many of the languages of
Asia, Africa, and aboriginal America there are whole classes of sounds
that most of us have no knowledge of. They are not necessarily more
difficult of enunciation than sounds more familiar to our ears; they
merely involve such muscular adjustments of the organs of speech as we
have never habituated ourselves to. It may be safely said that the total
number of possible sounds is greatly in excess of those actually in
use. Indeed, an experienced phonetician should have no difficulty in
inventing sounds that are unknown to objective investigation. One reason
why we find it difficult to believe that the range of possible speech
sounds is indefinitely large is our habit of conceiving the sound as a
simple, unanalyzable impression instead of as the resultant of a number
of distinct muscular adjustments that take place simultaneously. A
slight change in any one of these adjustments gives us a new sound which
is akin to the old one, because of the continuance of the other
adjustments, but which is acoustically distinct from it, so sensitive
has the human ear become to the nuanced play of the vocal mechanism.
Another reason for our lack of phonetic imagination is the fact that,
while our ear is delicately responsive to the sounds of speech, the
muscles of our speech organs have early in life become exclusively
accustomed to the particular adjustments and systems of adjustment that
are required to produce the traditional sounds of the language. All or
nearly all other adjustments have become permanently inhibited, whether
through inexperience or through gradual elimination. Of course the power
to produce these inhibited adjustments is not entirely lost, but the
extreme difficulty we experience in learning the new sounds of foreign
languages is sufficient evidence of the strange rigidity that has set in
for most people in the voluntary control of the speech organs. The point
may be brought home by contrasting the comparative lack of freedom of
voluntary speech movements with the all but pe