Purpose: Apraxia of speech (AOS) is a motor speech disorder affecting articulatory planning and speech programming. When AOS is the sole manifestation of neurodegeneration, it is termed primary progressive apraxia of speech (PPAOS). Recent work has shown that there are distinct PPAOS subtypes: phonetic, prosodic, and those that do not clearly…

Purpose: Phonetic training has been found to be an effective way on second language (L2) learning, but the evidence is not conclusive regarding the effectiveness of different instructional approaches and possible interactions between language learners, training features, and outcome measures. This study aims to meta-analyze existing studies to…

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: Pitch variations (tone productions) have been reported as a measure to differentiate Cantonese-speaking children with and without childhood apraxia of speech (CAS). This study aims to examine fundamental frequency (F0) changes within syllables and the effects of syllable structure, lexical status, and syllable positions on F0 in…

Purpose: We evaluated whether children whose inaccurate /[voiced alveolar approximant]/ productions showed evidence phonetic differentiation with /w/ at 3.5-4.5 years of age improved in /[voiced alveolar approximant]/ production over the next year more than children whose inaccurate productions did not show evidence of such differentiation. We…

Purpose: This study aimed to examine the effects of wearing a face mask on speech acoustics and intelligibility, using an acoustic-phonetic analysis of speech. In addition, the effects of speakers' behavioral modification while wearing a mask were examined. Method: Fourteen female adults were asked to read a set of words and sentences under three…

Purpose: It has been reported that children and adults weight differently the various acoustic properties of the speech signal that support phonetic decisions. This finding is generally attributed to the fact that the amount of weight assigned to various acoustic properties by adults varies across languages, and that children have not yet…

It has been hypothesized that lax vowels may be relatively unaffected by dysarthria, owing to the reduced vocal tract shapes required for these phonetic events (G. S. Turner, K. Tjaden, & G. Weismer, 1995). It also has been suggested that lax vowels may be especially susceptible to speech mode effects (M. A. Picheny, N. I. Durlach, & L. D. Braida,…

Purpose: Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal airflow waveform, is in part attributable to the maximum area declination rate (MADR) and in part to the overall inertia of the air column of the vocal tract (lungs to…

Purpose: Little is known about the phonological aspects of derivational processes. Neutral suffixes (e.g., "-ness") that do not change stress and rhythmic or nonneutral suffixes (e.g., "-ity") that alter stem stress were used in a production task that explored developmental changes in phonological accuracy of derived English…

Naturalistic speech samples of 29 3-year olds diagnosed with specific expressive language delay were compared to 19 age-matched peers in order to determine their improvement in phonological skills since age two. Results revealed no significant differences in number of vocalizations, although there were differences in phonetic inventories,…

Contrastive feature hierarchies have been developed and used for some time in depicting typical phonological development and in guiding therapy decisions. Previous descriptions of feature use have been based on independent analyses and usually phonetic inventories. However, recent trends in phonology include a relational analysis of phonemic…

Lip and jaw movements were studied longitudinally in 19-month-old children as they acquired the voicing contrast for /p/ and /b/. A movement tracking system obtained lip and jaw kinematics as participants produced the target utterances /papa/ and /baba/. Laryngeal adjustments were also tracked through acoustically recorded voice onset time (VOT)…