Purpose: Talkers adapt their speech according to the demands of their listeners and the communicative context, enhancing the properties of the signal (pitch, intensity) and/or properties of the code (enhancement of phonemic contrasts). This study asked how mothers adapt their child-directed speech (CDS) in ways that might serve the immediate goals…

Background: Previous research has found that high-frequency energy of speech signals decreased while wearing face masks. However, no study has examined the specific spectral characteristics of fricative consonants and vowels and the perception of clarity of speech in mask wearing. Aims: To investigate acoustic-phonetic characteristics of fricative…

Purpose: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects bulbar functions including speech and voice. Voice onset time (VOT) was examined in speakers with ALS in early and late stages to explore the coordination of the articulatory and phonatory systems during speech production. Method: VOT was measured in nonword…

The original Spectral Correlation Index (SCI[underscore o]) is a measure of amplitude envelope distortion that has been used in several studies to predict behavioral results. Because the original SCI[underscore o] did not account for the differential contribution of particular frequency bands to speech intelligibility (i.e., band importance) or…

Purpose: The purpose of this study was to characterize the acoustic profile and to evaluate the intelligibility of vowel productions in prelingually deafened, Mandarin-speaking children with cochlear implants (CIs). Method: Twenty-five children with CIs and 20 age-matched children with normal hearing (NH) were recorded producing a list of Mandarin…

Purpose: This study examined the acoustic properties of Taiwanese (Southern Min) lexical tones produced in esophageal speech (ES) and pneumatic artificial laryngeal speech (PAL), including onset fundamental frequency (F0), slope of F0 contour, duration, and amplitude (intensity) of the vowel portion of syllables carrying seven Taiwanese tones.…

This study aimed to investigate the role that phonetic convergence plays in the acquisition of L2 segments. In particular, it examined whether phonetic convergence towards native speakers could help Arabic-speaking second-language (L2) learners of English improve their pronunciation of four problematic English segments (/p, v, [open-mid front…

The use of linking or glottalization contributes to the characteristic sound pattern of a language, and the use of one in place of the other may affect a speaker's comprehensibility and fluency in certain contexts. In this study, native speakers of Czech, a language that is associated with a frequent use of glottalization in vowel-initial word…

Over the past few decades, there has been considerable effort to find the mechanisms through which adult listeners can accommodate the rampant phonetic variation in natural speech. My dissertation concerns one source of variability: phonetic variation in speech produced by individuals with foreign accents. Mounting evidence shows that listeners…