Description and Classification of Vowels

Description and Classification of English Vowel Sounds

A vowel sound is produced when the air passes out freely through the mouth without any obstruction by the tongue, teeth, or lips. While producing vowel sounds, the vocal cords vibrate, and the shape of the mouth changes. The quality of a vowel mainly depends on the position of the tongue and the shape of the lips. English has a rich system of vowel sounds which can be classified in different ways for easy understanding and correct pronunciation.

1. Classification According to the Part of the Tongue Used

On the basis of which part of the tongue is raised, English vowels are classified into front vowels, central vowels, and back vowels.

(a) Front Vowels

Front vowels are produced when the front part of the tongue is raised towards the hard palate. The lips are usually spread, and the sound is bright.

Examples:
/iː/ in see, /ɪ/ in sit, /e/ in bed, /æ/ in cat

(b) Central Vowels

Central vowels are produced when the middle part of the tongue is raised. The lips remain neutral, and these vowels are very common in natural speech.

Examples:
/ʌ/ in cup, /ɜː/ in bird, /ə/ in about

(c) Back Vowels

Back vowels are produced when the back part of the tongue is raised towards the soft palate. The lips are generally rounded, and the sound is deep.

Examples:
/uː/ in food, /ʊ/ in book, /ɔː/ in law, /ɒ/ in cot

2. Classification According to Tongue Height

Vowels are also classified according to how high or low the tongue is raised in the mouth.

(a) Close (High) Vowels

In close vowels, the tongue is raised very close to the roof of the mouth, and the jaw is almost closed.

Examples:
/iː/ see, /ɪ/ sit, /uː/ food, /ʊ/ book

(b) Half-Close (High-Mid) Vowels

Here the tongue is slightly lower than in close vowels, and the jaw opens a little more.

Examples:
/e/ bed, /o/ go

(c) Half-Open (Low-Mid) Vowels

The tongue is slightly higher than in open vowels, and the mouth is moderately open.

Examples:
/ɛ/ bet, /ɔ/ law

(d) Open (Low) Vowels

In open vowels, the tongue is at the lowest position, and the mouth is wide open.

Examples:
/æ/ cat, /a/ father, /ɒ/ cot

3. Classification According to Lip Position

The shape of the lips also plays an important role in vowel production.

(a) Spread (Unrounded) Lips

The lips are stretched like a smile. These vowels are mostly front vowels and sound bright.

Examples:
/iː/ see, /ɪ/ sit, /e/ bed, /æ/ cat

(b) Neutral Lips

The lips are relaxed, neither spread nor rounded. These are usually central vowels.

Examples:
/ʌ/ cup, /ɜː/ bird, /ə/ about

(c) Rounded Lips

The lips form a circular shape. These are mostly back vowels and sound deep.

Examples:
/uː/ food, /ʊ/ book, /ɔː/ law, /o/ go

Summing Up:

English vowel sounds can be clearly understood through their classification based on the part of the tongue used, the height of the tongue, and the position of the lips. Front, central, and back vowels show the horizontal movement of the tongue, while close, mid, and open vowels show its vertical movement. Lip positions further modify the sound quality. This scientific classification helps learners improve pronunciation and understand the sound system of English more accurately.