International audienceThis study examined the impact on speech processing of regional phonetic/phonological variation in the listener's native language. The perception of the /e/-/E/ and /o/-/O/ contrasts, produced by standard but not southern French native speakers, was investigated in these two populations. A repetition priming experiment showed that the latter but not the former perceived words such as /epe/ and /epE/ as homophones. In contrast, both groups perceived the two words of /o/-/O/ minimal pairs (/pom/-/pOm/) as being distinct. Thus, standard-French words can be perceived differently depending on the listener's regional accent

Properties of syllable onset /l/ that depend on the voicing of the syllable coda were measured for four speakers, representing different non-rhotic British English accents that differ in their phonetic realisation of onset /l/ and in their system of phonological contrast involving onset /l/ and /r/. Onset /l/ was longer before voiced than voiceless codas for all four speakers, and darker for two of them as measured by lower F 2 frequency, and for these two and one other as measured by spectral centre of gravity (COG). There were no coda-dependent differences in f 0 in the /l/, and F 1 frequency differed only for the fourth speaker. The vowel was also longer for all four speakers when the coda was voiced (as expected), while F 1 was lower and F 2 normally higher. One speaker provided data with fricative or affricate onsets: fricated segments were longer before voiced codas, but no coda-dependent COG differences were found. At least when the onset includes /l/, phonological voicing of the coda seems to be reflected in complex acoustic-phonetic properties distributed across the whole syllable, some properties being localised, others not. We describe these properties as variations in a bright~sombre dimension. In most accents, when the coda is voiceless, the syllable is relatively bright: small proportions of periodic energy which is relatively high-frequency at the syllable edges, and a high proportion of silence or aperiodic energy. When the coda is voiced, the syllable is relatively sombre: a high proportion of periodic energy which is relatively low-frequency at the syllable edges, and relatively small amounts of silence and aperiodic energy. Other accents use other combinations, dependent on the phonetic and phonological properties of liquids in the particular accent. The association of onset darkness and coda voicing does not seem to be ascribable to anticipatory coarticulation of features essential to voicing itself; this observation provides support for nonsegmental models of speech perception in which fine phonetic detail is mapped directly to linguistic structure without reference to phoneme-sized segments.

Auditory and somatosensory systems play a key role in speech motor control. In the act of speaking, segmental speech movements are programmed to reach phonemic sensory goals, which in turn are used to estimate actual sensory feedback in order to further control production. The adult's tendency to automatically imitate a number of acoustic-phonetic characteristics in another speaker's speech however suggests that speech production not only relies on the intended phonemic sensory goals and actual sensory feedback but also on the processing of external speech inputs. These online adaptive changes in speech production, or phonetic convergence effects, are thought to facilitate conversational exchange by contributing to setting a common perceptuo-motor ground between the speaker and the listener. In line with previous studies on phonetic convergence, we here demonstrate, in a non-interactive situation of communication, online unintentional and voluntary imitative changes in relevant acoustic features of acoustic vowel targets (fundamental and first formant frequencies) during speech production and imitation. In addition, perceptuo-motor recalibration processes, or after-effects, occurred not only after vowel production and imitation but also after auditory categorization of the acoustic vowel targets. Altogether, these findings demonstrate adaptive plasticity of phonemic sensory-motor goals and suggest that, apart from sensory-motor knowledge, speech production continuously draws on perceptual learning from the external speech environment.