Articulatory Phonetics

Articulatory Phonetics

 phonetics is concerned with describing the speech sounds that occur in

the languages of the world. We want to know what these sounds are,

how they fall into patterns, and how they change in different circumstances.

Most importantly, we want to know what aspects of the sounds are

necessary for conveying the meaning of what is being said. The first job of

a phonetician is, therefore, to try to find out what people are doing when

they are talking and when they are listening to speech.

I will begin by describing how speech sounds are made. In nearly all

speech sounds, the basic source of power is the respiratory system pushing

air out of the lungs. Try to talk while breathing in instead of out. You will

find that you can do it, but it is much more inefficient than superimposing

speech on an outgoing breath.

Air from the lungs goes up the windpipe (the trachea, to use the more,

technical term) and into the larynx, at which point it must pass between

two small muscular folds called the vocal cords. If the vocal cords are

apart, as they normally are when breathing out, the air from the lungs will

have a relatively free passage into the pharynx and the mouth. But if the

vocal cords are adjusted so that there is only a narrow passage between

them, the airstream will cause them to vibrate. Sounds produced when the

vocal cords are vibrating are said to be voiced, as opposed to those in

which the vocal cords are apart, which are said to be voiceless.

In order to hear the difference between a voiced and a voiceless sound,

try saying a long v sound, which we will symbolize as [vvvvv]. Now compare

this with a long f sound [fffffl, saying each of them alternately-

[ffffvvvvvfffffvvvvv]. Both of these sounds are formed in the same way in

the mouth. The difference between them is that [v] is voiced but [fl is

voiceless. You can feel the vocal cord vibrations in [v] if you put your fingertips

against your larynx. You can also hear the buzzing of the vibrations

in [v] more easily if you stop up your ears while contrasting [fffffvwvv].

The difference between voiced and voiceless sounds is often important

in distinguishing sounds. In each of the pairs of words "fat, vat; thigh, thy;

Sue, zoo" the first consonant in the first word of each pair is voiceless,

whereas in the second word, it is voiced. To check this for yourself, say

just the consonant at the beginning of each of these words and try to feel

and hear the voicing as suggested above. Try to find other pairs of words

that are distinguished by one having a voiced and the other having a voiceless

consonant. 0

The air passages above the larynx are known as the vocal tract

The shape of the vocal tract is a very important factor in the production of

speech,  Note that the air passages that

make up the vocal tract may be divided into the oral tract within the mouth

and pharynx, and the nasal tract within the nose. The upper limit of the

nasal tract has been marked with a dotted line since the exact boundaries of

the air passages within the nose depend on soft tissues of variable size.

The parts of the vocal tract that can be used to fom sounds are called

articulators. The articulators that form the lower surface of the vocal tract

often move toward those that form the upper surface. Try saying the word

"capital" and note the major movements of your tongue and lips. You will

find that the back of the tongue makes contact with the roof of the mouth

for the first sound and then comes down for the following vowel. The lips

come together in the formation of p and then come apart again in the

vowel. The tongue tip comes up for the t and again, for some people, for

the final 1.

The names for the principal parts of the upper surface of the vocal tract

. The upper lip and the upper teeth (notably the

frontal incisors) are familiar enough structures. Just behind the upper teeth

is a small protubeiance that you can feel with the tip of the tongue.

called the alveolar ridge. You can also feel that the front part of the roof

of the mouth is formed by a bony structure. This is the hard palate. You

will probably have to use a fingertip to feel further back. Most people cannot

curl the tongue up far enough to touch the' soft palate, or velum, at the

back of the mouth. The soft palate is a muscular flap that can be raised to

press against the back wall of the pharynx and shut off the nasal tract, preventing

air from going out through the nose. In this case there is said to be

velic closure. This action separates the nasal tract from the oral tract so

that the Bir can go out only through the mouth. At the lower end of the soft

palate is a small appendage hanging down that is known as the uvula. The

part of the vocal tract between the uvula and the larynx is the pharynx. The

back wall of the pharynx may be considered to be one of the articulators

on the upper surface of the vocal tract. Figure 1.3 shows the lower lip and

the specific names for different parts of the tongue that form the lower surface

of the vocal tract:

 The principal parts of the lower surface of the vocal tract.

The tip and blade of the tongue are the most mobile parts. Behind the

blade is what is technically called the front of the tongue: it is actually the

forward part of the body of the tongue, and lies underneath the hard palate

when the tongue is at rest. The remainder of the body of the tongue may be

divided into the center, which is partly beneath the hard palate and partly

beneath the soft palate, the back, which is beneath the soft palate, and the

root, which is opposite the back wall of the pharynx. The epiglottis is

attached to the lower part of the root of the tongue.

Bearing all these terms in mind, say the word "peculiar" and try to give

a rough description of the actions of the vocal organs during the consonant

sounds.