Child speech is highly variable. The speech apparatus--the vocal tract, tongue, teeth, and vocal folds--develop at different rates for different children, which helps explain some of the variability in children's speech. For example, the ratio of the oral to pharyngeal cavities changes as children age, making it difficult to establish reliable…

Purpose: In this study, the authors compared coarticulation and lingual kinematics in preadolescents and adults in order to establish whether preadolescents had a greater degree of random variability in tongue posture and whether their patterns of lingual coarticulation differed from those of adults. Method: High-speed ultrasound tongue contour…

Purpose: Children acquire /-ez/ syllabic plurals (e.g., buses) later than /-s, -z/ segmental plurals (e.g., cats,dogs). In this study, the authors explored whether increased syllable number or segmental factors best explains poorer performance with syllabic plurals. Method: An elicited imitation experiment was conducted with 14 two-year-olds…

Purpose: This study investigated how different instructions for eliciting clear speech affected selected acoustic measures of speech. Method: Twelve speakers were audio-recorded reading 18 different sentences from the Assessment of Intelligibility of Dysarthric Speech (Yorkston & Beukelman, 1984). Sentences were produced in habitual, clear,…

This dissertation explores a purportedly unusual word type known as the "sesquisyllable," which has long been considered characteristic of mainland Southeast Asian languages. Sesquisyllables are traditionally defined as "one and a half" syllables, or as one "major" syllable preceded by one "minor" syllable,…

This article reports the results of a multiparametrical analysis of "Mongolian Long Song," characterised by multiple ornamentation and shows the similarities between the laryngeal behaviour observed during these ornamentations and the compensatory gesture produced by patients after supracricoid partial laryngectomy. This study includes…

Purpose: Adult human vocal tracts display considerable morphological variation across individuals, but the nature and extent of this variation has not been extensively studied for many vocal tract structures. There exists a need to analyze morphological variation and, even more basically, to develop a methodology for morphological analysis of the…

Purpose: Differences in vocal tract morphology have the potential to explain interspeaker variability in speech production. The potential acoustic impact of hard palate shape was examined in simulation, in addition to the interplay among morphology, articulation, and acoustics in real vowel production data. Method: High-front vowel production from…

Talkers are known to compensate only partially for experimentally-induced changes to their auditory feedback. In a typical experiment, talkers might hear their F1 feedback shifted higher (so that /[epsilon]/ sounds like /[ash]/, for example), and compensate by lowering F1 in their subsequent speech by about a quarter of that distance. Here, we…

The present acoustic-phonetic study explores whether voicing and devoicing assimilations of French fricatives are equivalent in magnitude and whether they operate similarly (i.e., complete vs. gradient, obligatory vs. optional, regressive vs. progressive). It concurrently assesses the contribution of speakers' articulation rate to the proportion…

Purpose: Delayed auditory feedback (DAF) is known to induce stuttering-like disfluencies (SLDs) and cause speech rate reductions in normally fluent adults, but the reason for speech disruptions is not fully known, and individual variation has not been well characterized. Studying individual variation in susceptibility to DAF may identify factors…

Purpose: The authors compared articulatory contact pressure (ACP), oral air pressure (Po), and speech acoustics for conversational versus clear speech. They also assessed the relationship of these measures to listener perception. Method: Twelve adults with normal speech produced monosyllables in a phrase using conversational and clear speech.…

Purpose: With the goal of using articulatory adjustments to reduce hypernasality, this study utilized an articulatory synthesis model (Childers, 2000) to simulate the adjustment of articulatory configurations with an open velopharynx to achieve the same acoustic goal as normal speech simulated with a closed velopharynx. Method: To examine the…

Purpose: The purpose of this study was to determine listeners' ability to learn talker identity from speech produced with an electrolarynx, explore source and filter differentiation in talker identification, and describe acoustic-phonetic changes associated with electrolarynx use. Method: Healthy adult control listeners learned to identify…

Purpose: To improve lingual ultrasound imaging with the Corrected High Frame Rate Anchored Ultrasound with Software Alignment (CHAUSA; Miller, 2008) method. Method: A production study of the IsiXhosa alveolar click is presented. Articulatory-to-acoustic alignment is demonstrated using a Tri-Modal 3-ms pulse generator. Images from 2 simultaneous…