Purpose: In this study, we examined the utility of vowel intelligibility testing for assessing the impact of dysarthria on speech characteristics in people with amyotrophic lateral sclerosis (ALS). We tested the sensitivity and specificity of overall vowel identification, as well as that of vowel-specific identification, to dysarthria presence and…

Purpose: This study examined how speakers adapt to fundamental frequency (f[subscript o]) errors that affect the use of prosody to convey linguistic meaning, whether f[subscript o] adaptation in that context relates to adaptation in linguistically neutral sustained vowels, and whether cue trading is reflected in responses in the prosodic cues of…

This dissertation examined two phonological and morphological changes in Ghamdi Arabic (GA), focusing on vowel harmony and gender distinctions. By comparing Prochazka's 1988 findings with recent data from 26 participants across two age groups. Participants consisted of 20 younger speakers (10 males and 10 females, ages 20 to 35) and six older…

The present study aims to investigate the identification of native vowel categories by adult individuals with Autism Spectrum Disorder (ASD) and estimate their reaction times in both normal and whisper registers; their responses were compared with those of typically developing individuals. The results demonstrated that there was no deficit for…

Purpose: The effect of onset asynchrony on dichotic vowel segregation and identification in normal-hearing (NH) and hearing-impaired (HI) listeners was examined. We hypothesized that fusion would decrease and identification performance would improve with increasing onset asynchrony. Additionally, we hypothesized that HI listeners would gain more…

This study analyses the production of French /y/ and /u/ by 42 native English learners of French (ELoF) at the start and end of a Residence Abroad (RA) in a French-speaking country. As an approximation of both phonological and phonetic development, categorical change is teased apart from gradient change using k-medoid clustering of acoustic data…

Purpose: Atypical vowel production contributes to reduced speech intelligibility in children and adults with Down syndrome (DS). This study compares the acoustic data of the corner vowels /i/, /u/, /ae/, and /[open back unrounded vowel]/ from speakers with DS against typically developing/developed (TD) speakers. Method: Measurements of the…

Purpose: Envelope following responses (EFRs) could be useful for objectively evaluating audibility of speech in children who are unable to participate in routine clinical tests. However, relative to adults, the characteristics of EFRs elicited by frequency-specific speech and their utility in predicting audibility in children are unknown. Method:…

Purpose: The goal of this study was to explore the relationships among vocal effort, extrinsic laryngeal muscle activity, and vocal tract length (VTL) within healthy speakers. We hypothesized that increased vocal effort would result in increased suprahyoid muscle activation and decreased VTL, as previously observed in individuals with vocal…

Purpose: Auditory feedback perturbation with voice pitch manipulation has been widely used in previous studies. There are several hardware and software tools for such manipulations, but audio plug-ins developed for music, movies, and radio applications that operate in digital audio workstations may be extremely beneficial and are easy to use,…

The ability to process plural marking of nouns is acquired early: at a very young age, children are able to understand if a noun represents one item or more than one. However, little is known about how the segmental characteristics of plural marking are used in this process. Using eye-tracking, we aim at understanding how five to twelve-year old…

This paper addresses how input variability in the adult phonological system is mastered in the output of young children in Akan, a Kwa language spoken in Ghana, involving variability between labio-palatalized consonants and front rounded vowels. The high-frequency variant involves a complex consonant which is expected to be mastered late, while…

The current study explored individual differences in sensitivity to sub-phonemic variation of acoustic cues in the perception of a native language (L1) category in order to test the hypothesis that second language (L2) learners' different sensitivity to the L2-relevant acoustic dimension in L1 perception could explain individual variability in…

Purpose: The purpose of this study was to investigate how general, implicit instructions with auditory-perceptual emphasis; specific, explicit instructions with biomechanical focus; or both affect learning of oral-nasal balance control in speech. Method: Thirty healthy, vocally untrained participants were assigned to one of three instructional…

Purpose: This study examined the speech acoustic characteristics of Jamaican Creole (JC) and English in bilingual preschoolers and adults using acoustic duration measures. The aims were to determine if, for JC and English, (a) child and adult acoustic duration characteristics differ, (b) differences occur in preschoolers' duration patterns based…