Pholas

3719

Phonograph

Pholas, a genus of burrowing bivalve mol-
luscs, whose members are known as pid-
docks or date shells. Like all burrowing
bivalves, they have gaping shells, which are
open at both ends, and have accessory plates
of lime attached. In Southern Europe and
in some other countries these molluscs are
eaten, or esteemed valuable as bait.

Phonetics is the science of speech sounds,
and deals with their character, relations,
combinations, and changes. Speech sounds
are best denned in terms of the manner
in which they are produced by vocal or-
gans. Acoustical descriptions in which words
such as 'soft' and 'flat' are employed convey
no clear conception of the character of
sound, and are altogether valueless as aids
to pronunciation. A description of the posi-
tion occupied by the vocal organs when a
particular sound is formed provides a defi-
nite means of comparison with other sounds,
and is also an indication of how an unknown
sound may be produced. The physiology of
the vocal organs is an important auxiliary
in the study of phonetics. Speech sounds
may be broadly classified according as the
breath by which they are produced streams
through the mouth channel or the nose
channel, or through both together. Several
additional factors also contribute to the
production of distinctive sounds. The part
played by the glottis, the opening between
the vocal cords, is important. The manner
in which the lips are set is another modify-
ing influence in the production of speech.

What follows is a summary statement re-
garding the principal groups of speech
sounds. The stop consonants are formed
by cutting off the stream of breath and sud-
denly releasing it again. They include p, t,
k, bt d, and others.

Spirant consonants are also known as
fricatives or continuants. Corresponding to
the stop series is a spirant series, / (wh),
th, kh, v (w), dh, gh, in which the stream
of breath is only checked, not stopped, by
the lips, point of the tongue, and back of
the tongue respectively. Another set of
spirants are the sibilants, s, z, sh, and zh.
is voiced s9 and zh voiced sh. The blade of
of the tongue (Sweet's expression for the
part immediately behind the point) seems
to be prominent in the formation of s, but
other factors also help to determine its
character. There is a whole series of s's, al-
most parallel to the th series, with which
it is frequently confused by speakers whose

native language contains no th. sfi is defined
by Sweet as 'point-blade/ L and r are closely
related in the manner of their formation,
and therefore also in the history of Ian-
gauge. The sounds denoted by r are a some-
what miscellaneous group. Those who are
familiar with trilled r's regard the trill as
their most important feature. Nasals.—In the
formation of nasal sounds the mouth passage
is closed by the lips (;w), the point of the
tongue (H) , or the back of the tongue (ng),
and the breath escapes through the nostrils,
There are varieties of nasals similar to the va-
rieties observed in the case of the stop conso-
nants. In particular the front and back varie^
ties of ng are to be distinguished. Voiceless m,
n, and ng occur regularly in Welsh. Vowel
Sounds.—The factors which determine the
character of vowel sounds are chiefly the
point of articulation by the tongue and the
height to which it is raised; further, the
part played by the lips and the nasal pas-
sages. Some have made tables including 72
vowel sounds, divided into back vowels;
front vowels; mixed vowels; and nasal
vowels. Consult L. Soames' Introduction to
English, French and German Phonetics (rev.
by W. Victor), for a beginner; E. Scrip-
ture's Elements of Experimental Phonetics;
Tilly's The Problem of Pronunciation
(1925) ; Prendergast's Good American
Speech (1930).

Phonograph, a term generally applied to
any machine which records and reproduces
sound, though it is sometimes restricted to
the particular type of machine developed by
Edison and his associates. There are two
classes of sound recording machines: the
cylinder machine, in which the sound is
recorded upon a wax cylinder, and the disc
machine, in which a flat circular disc is
substituted for the cylinder. The phono-
graph and graphophone make a verticle
record of the sound waves, while the gramo-
phone records the sound in horizontal curves.
The word phonograph is generally used to
include both types. The first real attempt
at recording sound was made by Leon Scott,
a Frenchman who, in 1857, invented his
phonautograph, a machine which bore a
striking resemblance to the early phono-
graphs; but the sound he recorded could
not be reproduced. Cros, another French-
man, wrote an article telling how Scott's
machine could be made to reproduce sound
in 1877. In the same year Thomas Edison,
produced a machine that was successful both