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30 THE ARTICULATORY APPARATUS.
placing of the voice a resistance is given to the top of the vibrating column of air in speech and song.
38. The Mouth.—The mouth is a large resonating cavity forming the lower of the two apertures by which the air and voice escape from the body (Fig. 16) ; it is separated from the other aperture, the nose, by the palate, which forms the roof of the mouth and the floor of the nose; the front part of the palate consists of bone, which is fixed and is cabled the hard palate; the back part is muscle, which is very movable and is called the soft palate. The soft palate is prolonged into two arches at the side called the arches of the palate (or pillars of the fauces), and into a grape-like projection in the centre called the uvula; these prolongations consisting of muscle can be contracted and moved in such a way as to cut off either the mouth or the nose from the lower pharynx, in which action they are helped by the constrictors. They can also so modify the shape of the back of the mouth as to make considerable difference to the resonance.
39. The Tongue.—At the bottom of the mouth is the tongue, which can completely alter the shape and resonance of this cavity; it is a muscular organ which can move in all directions, forwards, backwards, upwards, downwards, from side to side, either as a whole or in part, so that the tip, middle, or back can be moved separately; it can be folded upwards and downwards or at the sides, and can be made to vibrate (Fig. 17). It can prevent any air from going into the mouth by being raised to meet the soft palate at the back, as when sounding NO, K, or O, or it can stop the air farther forward in the mouth by its tip being made to touch the hard palate just behind the upper front teeth, as when sounding N, T, or D, or a little