Velarization
It is a general term referring to any SECONDARY ARTICULATION involving a movement of the back part of the tongue towards the velum. For a sound to be velarized, of course, its primary place of articulation must be elsewhere in the mouth, e.g. a [z] sound, normally made in ALVEOLAR position, is said to be velarized if during its articulation the back of the tongue is raised towards the soft palate; this would give the sound a distinctive back (or ‘dark’) resonance. The term is usually applied to consonants other than velar consonants; it can be used with reference to VOWELS, but such variations in vowel articulation are usually described in different terms (‘centralized’, ‘retracted’, etc.). The velarization may be an essential feature of the sound’s identity, contrasting with other non-velarized sounds, as in the distinction between velarized and non-velarized s in Arabic (transcribed 
and [s] respectively). In English, velarization is dependent on context: syllable-final l, as in cool, is given a velar resonance; this can be compared with syllable-initial l, as in leap, where the back of the tongue is much further forward in the mouth (towards the palate).
A loose auditory label for velar resonance sounds is ‘dark’ (Dark L, etc.), opposed to ‘clear’, used for the palatal-resonance sounds. The usual symbol for velarized consonants is [~], placed through the letter, as in 
. Some dialects, such as those of the English Midlands (Birmingham, Wolverhampton, etc.), have several velarized sounds.
