!e coarticulatory basis of diachronic high back vowel fronting*

!e study is concerned with the contribution of synchronic consonant-on-vowel coarticulation to the diachronic fronting of high back vowels. !e "rst part of the paper makes use of an empirical analysis of German vowels to explain why high back vowels are more likely to front diachronically than high front vowels are to retract. !is study is then linked to the changing coarticulatory relationships in the course of diachronic high back vowel fronting in the standard accent of England. !e results show that this sound change in progress has resulted in a phonologization of the variants in a fronting context and a consequential realignment in perception of the back variants towards the front. !e general conclusion is that the wide separation of phonetic variants induced by consonantal context provides the conditions for high back vowel fronting which can be ful"lled during a sound change in progress by their progressive approximation in perception and production.