Figure 3.
Figure 4 shows the position of the lips for the vowel sound of long o. The opening of the lips should be made as round as is the letter o. When preparing the lips to give the sound of o, the inclination is strong to drop the lower jaw; in practice, to develop action of the lips, the under jaw would better be held quite immovable. It will be found possible to produce all of the vowel sounds without any change except in the form of the opening of the lips. The vowel sound of i is an exception; for as a compound of ah and ee, the extremes of the vowel scale, it requires two distinct positions for its utterance with a movement of transition between; it is not, therefore, a good vowel for initial practice.
Figure 4.
Figure 5 shows that the sound aw is produced from o by raising the edge of the upper lip outward and upward, and flattening the raised portion laterally.
Figure 5.
Figure 6 shows the position for producing ah. It differs from the position assumed for aw in that the opening of the lips is larger, the upper lip is raised higher, the flat portion is wider, and the under lip is a little relaxed. The form of the opening to produce aw is oval; the form for ah is more nearly square.
Figure 6.