Reassignment of consonant allophones in rapid dialect acquisition

••A variant of one phoneme can be recruited for realization of another phoneme in dialect imitation.••Speakers generalize the new pattern from training materials to untrained lexical items.••However, speakers use the newly learned pattern more reliably with training items.••Speakers also attempted to approximate the D2 sound parametrically.••A hybrid model is proposed that reconciles these findings with previously found exemplar effects.

In an experiment spanning a week, American English speakers imitated a Glaswegian (Scottish) English speaker. The target sounds were allophones of /t/ and /r/, as the Glaswegian speaker aspirated word-medial /t/ but pronounced /r/ as a flap initially and medially. This experiment therefore explored (a) whether speakers could learn to reassign a sound they already produce (flap) to a different phoneme, and (b) whether they could learn to reliably produce aspirated /t/ in an unusual phonological context. Speakers appeared to learn systematically, as they could generalize to words which they had never heard the Glaswegian speaker pronounce. The pattern for /t/ was adopted and generalized with high overall reliability (96%). For flap, there was a mix of categorical learning, with the allophone simply switching to a different use, and parametric approximations of the “new” sound. The positional context was clearly important, as flaps were produced less successfully when word-initial. And although there was variability in success rates, all speakers learned to produce a flap for /r/ at least some of the time and retained this learning over a week's time. These effects are most easily explained in a hybrid of neo-generative and exemplar models of speech perception and production.