Phonetic Implementation of Prosodic Emphasis in Preschool-Aged Children and Adults: Probing the Development of Sensorimotor Speech Goals

Abstract

Objective We aimed to investigate the production of contrastive emphasis in French-speaking 4-year-olds and adults. Based on previous work, we predicted that, due to their immature motor control abilities, preschool-aged children would produce smaller articulatory differences between emphasized and neutral syllables than adults. Method Ten 4-year-old children and 10 adult French speakers were recorded while repeating /bib/, /bub/, and /bab/ sequences in neutral and contrastive emphasis conditions. Synchronous recordings of tongue movements, lip and jaw positions, and speech signals were made. Lip positions and tongue shapes were analyzed; formant frequencies, amplitude, fundamental frequency, and duration were extracted from the acoustic signals; and between-vowel contrasts were calculated. Results Emphasized vowels were higher in pitch, intensity, and duration than their neutral counterparts in all participants. However, the effect of contrastive emphasis on lip position was smaller in children. Prosody did not affect tongue position in children, whereas it did in adults. As a result, children's productions were perceived less accurately than those of adults. Conclusion These findings suggest that 4-year-old children have not yet learned to produce hypoarticulated forms of phonemic goals to allow them to successfully contrast syllables and enhance prosodic saliency.

The Prosody of Two-Syllable Words in French-Speaking Monolingual and Bilingual Children: A Focus on Initial Accent and Final Accent

“…Important to note, however, is that Vihman and colleagues (1998) did not take into consideration the intonation of French in which initial syllables may optionally receive a pitch accent. More recently, Ménard and colleagues have investigated the acoustic and articulatory correlates of contrastive focus in French-speaking children and adults (Ménard et al, 2006;Ménard et al, 2020;Rapin & Ménard, 2019). Contrastive focus is a type of narrow focus in which the speaker gives emphasis to a specific constituent as opposed to emphasizing another constituent in a paradigmatic comparison (e.g., the word John receives contrastive focus in the sentence "No, I saw John" in response to the question "Did you see Mary?").…”

“…One of the principal aims of the study was to provide information on the presence of initial accent in child speech. Indeed, we are unaware of any previous study which has investigated initial accent in a young French-speaking population (with the exception of studies by Ménard et al (2006Ménard et al ( , 2020, which have studied contrastive stress). We observed that despite its optional nature in adult speech, it is employed frequently by young children and its presence diminishes over time.…”

“…Contrastive focus is a type of narrow focus in which the speaker gives emphasis to a specific constituent as opposed to emphasizing another constituent in a paradigmatic comparison (e.g., the word John receives contrastive focus in the sentence “No, I saw John” in response to the question “Did you see Mary?”). Ménard et al (2020) report that children as young as four years are able to use acoustic correlates, F0, amplitude, and duration, as well as adults when going from a neutral to a focused condition. In contrast, they have not acquired the articulatory correlates of contrastive focus, making less use of lip and finely tuned tongue gestures.…”