Robert Burden’s Read Write Scene Site

Vowels are classified with features that are different from those of consonants because the articulator (i.e., the tongue) does not make contact to stop or fricate the air pressure.  Whereas consonants are known by voicing, place of articulation, and manner of articulation, vowels are classified by vertical position of the tongue, horizontal position of the tongue, and the state of the articulating muscles involved.  Vowels are not classified by vocalization (i.e., voice) because all vowels are voiced, so there is no need to distinguish them in that area; it’s a given.  Although vertical and horizontal positions of the tongue indicate a kind of place of articulation, since there is no contact between the tongue and other parts of the mouth, they do not relate to the place of consonant articulation, so they are just classified by the general position of the tongue.  The lip muscles and cheek mustles are involved more prominantly with American vowel sounds.  Whereas front vowels use the tense or lax status of the cheek muscles, back vowels use the tense or lax status of the lip muscles and central vowels use the tense or lax status of the tongue.