In articulatory phonetics, a consonant's a speech sound that's articulated with complete or partial closure of the upper vocal tract, the upper vocal tract being defined as that part of the vocal tract that lies above the larynx. Consonants contrast with vowels. Since the number of consonants in the world's languages's much greater than the number of consonant letters in any one alphabet, linguists have devised systems such as the (IPA) to assign a unique symbol to each attested consonant. In… (More on Consonant)