The letters e, i, and y in unstressed syllables represent a very laxly articulated sound, for which the sign is used in this book. It varies somewhat in different speakers; several sounds intermediate between the open [ɪ] and the middle [e] may be heard. This serves to explain the uncertainty of spelling in such cases as ensure and insure, enquire and inquire.
Sometimes the vowel disappears altogether, as in business, medicine, venison.
The letter o in unstressed syllables preceding the chief stress is usually [ə], but in precise speech an o-sound is heard in such words as conceive, official, possess. After the chief stress [ɔ] is rarely heard; but epoch [ijpɔk] and other uncommon words keep the [ɔ].
39. The front vowels.—Utter the word he and notice what the tongue does. You can do so by looking into your mirror, or by putting a finger just inside your front upper teeth, or by whispering the sound, and feeling what happens.
You will generally find that you can analyse vowels best if you whisper them, because the "voice" does not interfere with your appreciation of the mouth resonances. By this time your muscular consciousness (see § 9) should be considerably developed, and you should be conscious of what your tongue, lips, etc., are doing, without having recourse to a mirror.
You will find that you are raising your tongue very high in front: [ɑ] and are extremes; in the one case the front of the tongue is practically as low as it can be, in the other it is raised as high as possible. You might raise the tongue farther, but the resulting sound would not be a vowel. The passage would be too narrow, there would be friction, and a continuant would be the result (see § 34).
Utter a pure [ɑ] and gradually raise the front of the tongue until you reach . You may either keep your vocal chords vibrating all the time, or you may whisper the sounds; but see that the tongue moves slowly and steadily. You will realise that very many sounds lie between [ɑ] and ; as they are all produced with the raising of the front of the tongue, they are called front vowels.
We have already noticed clear [a], and have met with [æ], which is the vowel sound in hat [hæt]. When unstressed the [æ] gives place to [ə]; that [ðæt] becomes [ðət].
The uneducated sometimes substitute a closer sound (the middle e) for [æ]; they say [keb] for cab, [ketʃ] for catch, [θeŋks] for thanks, [beŋk] for bank. The same mistake may also be heard in the pronunciation of carriage, radish, January. In any, many the first vowel is always [e]. What is it in manifold?