ARTICULATORS IN ARTICULATION

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 teet (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.

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.