The relationship between the perception and production of coarticulation during a sound change in progress.

The present study is concerned with lax /u/-fronting in Standard British English and in particular with whether this sound change in progress can be attributed to a waning of the perceptual compensation for the coarticulatory effects of context. Younger and older speakers produced various monosyllables in which /u/ occurred in different symmetrical consonantal contexts. The same speakers participated in a forced-choice perception experiment in which they categorized a synthetic /I-u/ continuum embedded in fronting /s_t/ and non-fronting /w_l/ contexts. /u/ was shown to be fronted for the younger age group in both production and perception. Although there was no conclusive evidence that younger listeners compensated less for coarticulation than did older listeners, the size of the coarticulatory influence of consonantal context on /u/ in perception was found to be smaller than in production for the younger than for the older group. The findings are consistent with a model of sound change in which the perceptual compensation for coarticulation wanes ahead of changes that take place to coarticulatory relationships in speech production. As a result, the perception and production of coarticulation may be unusually misaligned with respect to each other for some speaker-listeners participating in a sound change in progress.