Comparing Velum Velocity in Québécois French Nasals

Résumé

Our previous research has found that nasal consonants and nasal vowels in Québécois French have a similar size of velopharyngeal port opening (VPO) [de Boer et al., under review]. Based on previous reports of a moderate positive correlation between VPO and velum velocity [Kollia et al., 1995, JASA., 98(3), 1313-24], we hypothesise that nasal consonants and nasal vowels will have similar velum velocities. This study compares the velocities of the opening and closing of the velopharyngeal port (VPP) between nasal consonants and nasal vowels in French. Data was collected from an X-ray videofluorographic database that contains sentence-level speech from 9 (5 male, 4 female) native speakers of Québécois French. Using ImageJ [Rasband, 2018], we tracked VPP opening and closing movements along the sagittal plane of the vocal tract. To measure the velocity of velum movement, we fitted simple linear regression models with the VPO of the opening and closing phases and used their slopes as a proxy for velocity. The effect of segment differences (nasal consonant vs. nasal vowel) on velocity was analysed using linear mixed-effects models. Results indicate that the velum has greater velocities during vowel production than during consonant production. This is contrary to our hypothesis that nasal consonants and nasal vowels would have similar velocities and suggests that velocity can also be influenced by sound type. It’s important to note that this difference might not be consistent across datasets.