Classification of speech sounds

Speech sounds are grouped into language units called phonemes. A phoneme may be thought of as the smallest contrastive language unit which exists in the speech of all people belonging to the same language community in the form of speech sounds and may bring about a change of meaning. The phoneme is functional unit, that means theat being opposed to other phoneme in the same phonetic context it is capable of differentiating the meaning. Speech sounds are divided into vowels and consonants. A vowel is a voiced produced in the mouth with no obstruction to the air stream. The air stream is weak. The tongue and the vocal cords are tense, the muscular tension is distributed more or less evently throughout the mouth cavity and pharynx.

A consonant is a sound produced with an obstruction to the air stream. The organs of speech are tense at the place of abstruction. In the articulation of voiceless consonants, the air stream is strong, while in voices consonants it is weaker. Vowels are sounds of pure musical tone while consonants may be either sounds noise prevails over tone or sounds in which tone prevails over noise. The number of letters differs from that of sounds. Thus there are twenty-six letters, but forty-four phonemes in English: twelve vowels, eight diphthongs and twenty-four consonants.