Speech sounds are of two types vowels and consonants . A consonant is a speech sound during the articulation of which there is an obstruction with in the oral cavity or a narrowing of the air passage by various organs of speech so that lung air escapes with audible friction . In other words , all speech -sounds necessitating a closure or narrowing ,which involves plosion or friction ,are called consonants .

Consonants are produced in one of the two ways : either there is a closing movement of one of the speech organs forming such a narrow constriction that it is possible to hear the sound of the air passing through or the closing movement may involve the lips ,the tongue or the throat . The over-all effect in each case is quite different from the open unobstructed articulation found in the case of vowels .

During the production of certain consonants , vocal cords vibrate . Those consonants that involve the vibration of vocal cords are called voiced consonants . During the production of the rest of the consonants ,vocal cords do not vibrate .Those consonants that are produced without the vibration of vocal cords are called voiceless consonants .This distinction ,however ,is not absolute .The position of the consonant in a word , to a great extent , determines the degree of voicing .For example , if a voiced consonant appears at the end of a word it loses a great deal of its vibration . The /z/ sound at the beginning of the word zebra /zi:bra/ is much more vibrant than the /z/ sound at the end of the word jazz /dzaez/.

CONSONANTS OF ENGLISH RP

There are 24 consonants in english RP. The following details regarding their production are necessary for the description of these consonants .

0. THE NATURE OF THE AIR STREAM MECHANISM
1. THE STATE OF THE GLOTTIS
2. THE POSITION OF THE SOFT PALATE
3. THE PLACE OF ARTICULATION
4. THE MANNER OF ARTICULATION