In “The Articulate Voice” chapter 9 “Vowels” by Lynn K. Wells explains the importance of International Phonetic Alphabet (IPA) that represent over 40 sounds from 26 letters in English alphabet. She reminds us “IPA Symbols is equals to sound not spelling “(p.147). Under the Approach to vowel study section, L.K. Wells give us the characteristics and classification of vowels.
All vowels are voiced and have vocal fold vibration.
In vowels production there is no breath interruption.
Shapes of the lips and tongue mass determine the sound.
Vowels have degree of tension or relaxation.
Vowels have different length.
Two type of Classification:
Vowels can be front, middle, or back.
High, mid, or low vowels.
Front Vowels Sounds
/ i / -- IPA symbol
Classified as high, front, tense vowel. Lips are in a tight, open smile; backsides of tongue are against upper morals. Examples: week /wik /; feel / fil /; eat /it /; tree/tri/. / I / --IPA symbol
Classified as high, front, relax vowel; lips are relaxed and slightly less smile that / i / symbol. Examples: did / dId /; if / If /; fill / fIl /; pin /pIn/. / eI / or / e / --IPA symbol
Classified as mid, front, tense vowel; lips are more tensed and in ”square” shape. Examples: make /mek /; bay /beIy /; eight /eIt /; locate /lokeIt /. / ε/ -- IPA symbol
Classified as mid, front, lax vowel. Lips are in “squared” shape with no tension. Tip of tongue is toward lower teeth; back of tongue barely touches back morals. Examples: let / lεt /; get / gεt /; pen / pεn /; bet /bεt/. / æ / -- IPA symbol
Classified as low, front, tense vowel. Lower jaw drops slightly from position for / ε/; tongue is almost touching the lower teeth and have slight degree of tension. Examples: bag /bæg/, cat /kæt/, act /ækt/.
Wells, Lynn K. (2004). “The Articulate voice.” 4th. Edition. Pearson 2004. (Pp.147-157).