An Introduction to French Pronunciation

14 The Production of Speech
when the air is retained in this way for certain kinds of
muscular effort such as lifting a heavy object.) The cords may
be drawn towards one another, not so much so as to block
the airstream entirely but close enough for them to vibrate
and produce voice (see 2.2.3). Alternatively, though this is
not the place to go into detail, various types of friction at the
vocal cords produce the English h sound or a whisper. (For
further information on the various types of sound produced
at the vocal cords, see for example Abercrombie, 1967: 25–8;
Catford, 2001: 49–53; Gimson, 2001: 10 –12.)
2.2.2 The space between the vocal cords is known as the
‘glottis’ and the corresponding adjective is ‘glottal’ (see in
particular 14.6).
2.2.3 In its technical sense, ‘voice’ is the sound produced by
rapid vibration (many times a second) of the vocal cords. It
is, therefore, a musical sound, produced in a similar way to
the sound produced by the vibration of the strings of a violin
or a piano or the vibration of the reed of a clarinet. Each
individual voice has of course a considerable range of pitch,
from high to low. The explanation for this is that the vocal
cords can be held in varying degrees of tension. The tenser
they are, the more frequently they vibrate and, consequently,
the higher the pitch.
The fundamental difference between, say, on the one hand
d and z and, on the other hand, t and s is that d and z are
accompanied by this vibration of the cords, i.e. by voice,
whereas t and s are not. On this basis, we can divide consonants
into two categories, voiced and voiceless (but see also
18.2 and 18.3). The sound of a voiceless consonant is not
musical – in reality, it is just noise.
For our present purposes, it can be assumed that all vowels
are voiced. (In reality, voiceless vowels can and do occur –
see 10.11.)