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Previous evidence suggests that children's mastery of prosodic modulations to signal the informational status of discourse referents emerges quite late in development. In the present study, we investigate the children's use of head gestures as it compares to prosodic cues to signal a referent as being contrastive relative to a set of possible alternatives. A group of French-speaking pre-schoolers were audio-visually recorded while playing in a semi-spontaneous but controlled production task, to elicit target words in the context of broad focus, contrastive focus, or corrective focus utterances. We analysed the acoustic features of the target words (syllable duration and word-level pitch range), as well as the head gesture features accompanying these target words (head gesture type, alignment patterns with speech). We found that children's production of head gestures, but not their use of either syllable duration or word-level pitch range, was affected by focus condition. Children mostly aligned head gestures with relevant speech units, especially when the target word was in phrase-final position. Moreover, the presence of a head gesture was linked to greater syllable duration patterns in all focus conditions. Our results show that (a) 4- and 5-year-old French-speaking children use head gestures rather than prosodic cues to mark the informational status of discourse referents, (b) the use of head gestures may gradually entrain the production of adult-like prosodic features, and that (c) head gestures with no referential relation with speech may serve a linguistic structuring function in communication, at least during language development.

Purpose: This work evaluates whether seeing the speaker's face could improve the speech intelligibility of adults with Down syndrome (DS). This is not straightforward because DS induces a number of anatomical and motor anomalies affecting the orofacial zone. Method: A speech-in-noise perception test was used to evaluate the intelligibility of 16 consonants (Cs) produced in a vowel-consonant-vowel context (Vo = /a/) by 4 speakers with DS and 4 control speakers. Forty-eight naïve participants were asked to identify the stimuli in 3 modalities: auditory (A), visual (V), and auditory-visual (AV). The probability of correct responses was analyzed, as well as AV gain, confusions, and transmitted information as a function of modality and phonetic features. Results: The probability of correct response follows the trend AV > A > V, with smaller values for the DS than the control speakers in A and AV but not in V. This trend depended on the C: the V information particularly improved the transmission of place of articulation and to a lesser extent of manner, whereas voicing remained specifically altered in DS. Conclusions: The results suggest that the V information is intact in the speech of people with DS and improves the perception of some phonetic features in Cs in a similar way as for control speakers. This result has implications for further studies, rehabilitation protocols, and specific training of caregivers.

Purpose: "Auditory verbal hallucinations" (AVHs) are speech perceptions in the absence of external stimulation. According to an influential theoretical account of AVHs in schizophrenia, a deficit in inner-speech monitoring may cause the patients' verbal thoughts to be perceived as external voices. The account is based on a predictive control model, in which individuals implement verbal self-monitoring. The authors examined lip muscle activity during AVHs in patients with schizophrenia to check whether inner speech occurred. Method: Lip muscle activity was recorded during covert AVHs (without articulation) and rest. Surface electromyography (EMG) was used on 11 patients with schizophrenia. Results: Results showed an increase in EMG activity in the orbicularis oris inferior muscle during covert AVHs relative to rest. This increase was not due to general muscular tension because there was no increase of muscular activity in the forearm muscle. Conclusion: This evidence that AVHs might be self-generated inner speech is discussed in the framework of a predictive control model. Further work is needed to better describe how inner speech is controlled and monitored and the nature of inner-speech-monitoring-dysfunction. This will lead to a better understanding of how AVHs occur.

Prosodic contrastive focus is used to attract the listener's attention to a specific part of the utterance. Mostly conceived of as auditory/acoustic, it also has visible correlates which have been shown to be perceived. This study aimed at analyzing auditory-visual perception of prosodic focus by elaborating a paradigm enabling an auditory-visual advantage measurement (avoiding the ceiling effect) and by examining the interaction between audition and vision. A first experiment proved the efficiency of a whispered speech paradigm to measure an auditory-visual advantage for the perception of prosodic features. A second experiment used this paradigm to examine and characterize the auditory-visual perceptual processes. It combined performance assessment (focus detection score) to reaction time measurements and confirmed and extended the results from the first experiment. This study showed that adding vision to audition for perception of prosodic focus can not only improve focus detection but also reduce reaction times. A further analysis suggested that audition and vision are actually integrated for the perception of prosodic focus. Visual-only perception appeared to be facilitated for whispered speech suggesting an enhancement of visual cues in whispering. Moreover, the potential influence of the presence of facial markers on perception is discussed. (Contains 3 tables and 8 figures.)