Classification of vowels

Classification of vowels:

Definition:

            A vowel is a speech sound.  In the production of vowel sounds,

·         there is the flow of air from the lungs in a continuous stream.

·         there is no obstruction.

·         there is vibration of vocal cords. and

·         the tongue remains stationary.

Kinds:

In Received Pronunciation (RP), there are 20 distinct vowels.  Of these, 12 are Pure vowels (Monophthongs) and 8 are Diphthongs (Vowel glides).

Vowels are classified according to

·         The part of the tongue raised.

·         The height of the tongue raised.

·         The position of lips and

·         The length of sound.

            Part of the Tongue:

                        On the basis of the part of the tongue, vowels are classified into

·         Front vowels: / iː/ , /ɪ /, / e /, / æ/

·         Back vowels: / ɑː/,/ ɒ /,/ ɔː/, / ʊ /, / uː/

·         Central vowels: / ʌ /,/ ɜː/, / ə /

Height of the Tongue:

            On the basis of the height of the tongue, vowels are classified into

·         Close vowels: / iː/, / uː/

·         Half close vowels:  /ɪ /, / ʊ /

§  Between half-close + half-open: / e /,/ ə /

§ 

Between half-open + half-close: / ɜː/

·         Half open vowels: / æ/, / ɔː/

·         Open: /ɑː/

§  Between open + half-open: / ɒ /, / ʌ /.

The Position of Lips:

·         Rounded vowels:  / ɒ /, / ɔː/, / ʊ /,/ ɑː/ / uː/and

·         Unrounded vowels: / iː/,  /ɪ /,  / e /,  / æ/, / ʌ /, / ɜː/, / ə /

  The Length Mark

According to the length of sounds, vowels are classified into

·         Long vowels: / iː/, /ɑː// ɔː/, / uː/, / ɜː/.

·         Short vowels: /ɪ /, / e /, / æ/, / ɑ/, / ʊ /, / ʌ /, / ə /.

The sign /ː/ is the length mark.  The long vowels are transcribed with the sign /ː/immediately after the vowel symbol.

Diphthongs:

The word ‘Diphthong’ comes from Greek. It means a double sound. In phonetics, it is a combination of two vowel sounds, one gliding into another. It makes a one unit of sound. Each vowel is uttered partially and merges into the other. A diphthong is like a long vowel and takes as much time for its articulation as the long vowel. It starts with one vowel and glides into another. Thus the two vowels glide into one sound. A diphthong belongs to one syllable. It is called a vowel glide: /eɪ /, / aɪ /, / ɔɪ/,  / əʊ / , / aʊ /, / ɪə /, / eə /,/ ʊə / .

Place of Articulation:

            In the production of a diphthong, the tongue is ready to utter a pure vowel but before this vowel is completed, the tongue moves on to produce the second vowel and here also, only half of vowel is uttered.

Classification:

         -     Closing Diphthongs

Diphthongs   

(Vowel glides)                     -  Centring Diphthongs

Closing Diphthongs:

            Closing diphthongs have the close vowel /ɪ /or / ʊ /as their final element. Therefore, they are called closing diphthongs.

            /eɪ /, / aɪ / ,/ ɔː/ ,/ əʊ / ,/ aʊ / : The second element is the close vowel.  Thus, there are 5 Closing diphthongs.

Examples: / eɪ/ Paid / peɪd /, / aɪ / Kind, / kaɪnd / , / ɔɪ/ Boy / bɔɪ/ , 

/ əʊ / Go, / gəʊ / , / aʊ / Cow / kaʊ/.

Centring diphthongs:

Centring diphthongs have the centre vowel /ə/ as the final element. Therefore, they are called Centring diphthongs: / ɪə /,  / eə / , / ʊə / . The second element is the centre vowel. Thus, there are 3 Centring diphthongs.

 Examples: / ɪə / dean / dɪə/,  / eə / share / ʃeə/,  / ʊə /tour / tʊə/.