2.3. T HE M AIN C RITERIA OF THE A RTICULATORY AND A COUSTIC C LASSIFICATION OF S PEECH S OUNDS S.F. Leontyeva draws our attention to the fact that articulatory
differences between vowels, consonants and sonorants depend on the
following criteria:
− the presence or absence of an articulatory obstruction to the air
stream in the larynx or in the supra-glottal cavities;
− the concentrated or diffused character of muscular tension;
− the force of exhalation.
On the basis of these criteria consonants may be defined as sounds in
the production of which (a) there is an articulatory obstruction to the air
stream (complete or incomplete); (b) muscular tension is concentrated in
the place of obstruction; (c) the force of exhalation is rather strong.
Vowels may be defined as sounds in the production of which (a)
there is no articulatory obstruction to the air stream; (b) muscular tension
is diffused; (c) the force of exhalation is rather weak.
26
Sonorants are sounds intermediate between noise consonants and
vowels because they have features common to both. The obstruction is
complete or incomplete, but narrow enough to produce noise. Muscular
tension is concentrated in the place of obstruction, but the force of
exhalation is rather weak. English sonorants are: [m, n, ŋ, l, w, r, j].