In a phonetic definition, vowels are distinguished from consonants in term of how they are articulated in the vocal tract and the associated patterns of acoustic energy.
When vowel sounds are produced, air escapes in a relatively unimpeded way through the mouth or nose. Such articulation involves only slight moments of the tongue and lips.
Vowels can, therefore, be defined as the sounds produced with neither a complete nor a narrowing of the vocal tract. Vowel sounds are produced when there is a free flow of air.
Vowel sounds can also be define as the sound in which there is no obstruction to the flow of air as it passes from the larynx to the lips. Vowels are normally described with reference to four criteria:
- The part of the tongue that is raised front, back, centre or lip.
- The extent to which the tongue raises in the direction of the palate-high, mid or low. Alternatively, tongue height can be described as close, mid-close, mid-open and open.
- The position of the soft palate-raised for oral vowels and lowered for nasalized vowels.
- The kind of opening made at the lips-various degrees of rounding or spreading.
TYPES OF VOWEL SOUNDS
The vowels sounds of English can be classified into three
THE MONOTHONGS
A vowel is monothongs or pure when only one sounds is involved. The monothongs are twelve. However, they are further divided into two groups thus: the short and long vowels.
- The Short Vowels: They are so called due to the brevity of the sounds the denote during speech process. They are as follows: /i/, /e/, /u/, /əe/, /ə/, /ɔ/, and /ʌ/. The seven short vowel sound can also be called lax vowels.
- The Fine Long Vowel: Which can also be called the tense vowels are fine. They include /i:, a:, ɔ:, u:, ɛ:/
THE TWELVE MONTHONGS
- /I:/ – This is a long sound, produced by raising the front of the tongue towards the hard palate; the lips are spread to a neutral position, and the air is forced through. Examples are found in words like read, see, chief, key be etc.
- /i/ – This is a short form of vowel one. it is produced by raising the front of the tongue towards the hand palate. Especially the central position of the palate, and the middle part of the tongue is raised slightly higher than half closed position and the lips are somewhat spread. Examples; fit, little, hill, ship etc.
- /e/ – The vowel is produced by raising the front of the tongue and the middle of the tongue to about half the distance between close and open, and the lips between being spread and neutral. Examples are in words like bet, egg, spread, pen, get, pet etc.
- /əe/ – This is produced by raising the blade of the tongue and the middle of the tongue raised to about one-sixth of the distance between open and close, and the lips between neutral and spread. Examples are in words like: – bad, mat, man, match, back, bag, etc.
- /a:/ – This vowel involves the back of the tongue unlike the previous ones, the middle of the tongue is quite low down in the mouth, and the lips are in the neutral position. Examples – father, calm, clerk, laugh, dark, saga, class, pass etc.
- /ɔ/ – This is articulated with the back of the tongue. While the lips are slightly rounded, the jam is usually open during pronunciation. The vowel is not quite fully back, and between open – mid and open in tongue height. Examples not, box, long, spot, bought, because, cop, cough, what, want etc.
- /ɔ:/ – This is the long variant of vowel 6. It is produced by raising the back of the tongue, slightly raising the middle of the tongue and rounding the lips very considerably. Examples – saw, law, caught, fought, cord, sword etc.
- /u/ – This sound is produced by raising the back of the tongue toward the soft palate (root of the mouth), raising the middle of the tongue in a little above half close position, and closely rounding the lips. It is short vowel with examples – put, foot, book, push, would, could, bought, woman, bosom, circular, bullet etc.
- /u:/ – This sound is mad right at the top and back of the mouth and the lips are moderately rounded. During production, the tongue is raised to a certain height towards the soft palate, the middle of the tongue is produced by raising the back of the tongue almost to close position and closely rounding the lips. Examples – two, food, moot, canoe, shoe, do, to, move, mute, rule, fruit, juice, suit etc.
- /ʌ/- This is a short sharp vowel, produced by raising the back of the tongue, though not fully, raising the middle of the tongue somewhat half way, and leaving the lips difficult sound for most Nigerians. Examples: cut, but mother, cup, stuck, done, some, sum, does, worry come, love, couple etc.
- / ɛ:/ – This is a long weak vowel, which is produced by raising the central part of the tongue and the lips in a central position. Is a central vowel that is often spelt “er”. It is pronounced “air” – – (r) – – (r). examples: fern, bird, girl, earth, journey, tournament, scourge, thirst, thirty, circuit, skirt etc.
- /ə/ – This is a short, weak vowel, which is produced by raising the central part of the tongue and the lips kept in a neutral position. It occurs mostly in unaccented syllables. It is called the schwa sound. It is generally not articulated with much energy. Examples: Mature, formula, curable, matter, doctor, neighbour, famous, confuse, today etc.
It is the most frequently occurring vowel for monothongs, it is usual to represent the position where each is articulated in the mouth.
See also:
DEMONSTRATIVE PRONOUNS
REFLEXIVE AND RELATIVE PRONOUNS
VOWELS /U/ AND /U:/