Purpose: One of the central questions in speech production research is to what degree certain structures have an inherent difficulty and to what degree repeated encounter and practice make them easier to process. The goal of this article was to determine the extent to which frequency and sonority distance of consonant clusters predict production…

Background: Parkinson's disease (PD) has an impact on speech production, manifesting in various ways including alterations in voice quality, challenges in articulating sounds and a decrease in speech rate. Numerous investigations have been conducted to ascertain the oral-diadochokinesis (O-DDK) rate in individuals with PD. However, the existing…

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…

Purpose: A critical component to the development of any type of intervention to improve speech production in individuals with Parkinson's disease (PD) is a complete understanding of the speech impairments present at each stage of the disease and how these impairments change with disease progression. The purpose of this longitudinal study was to…

Across languages, certain syllables are systematically preferred to others (e.g., "plaf > ptaf"). Here, we examine whether these preferences arise from motor simulation. In the simulation account, ill-formed syllables (e.g., "ptaf") are disliked because their motor plans are harder to simulate. Four experiments compared…

Purpose: Delayed auditory feedback (DAF) interferes with speech output. DAF causes distorted and disfluent productions and errors in the serial order of produced sounds. Although DAF has been studied extensively, the specific patterns of elicited speech errors are somewhat obscured by relatively small speech samples, differences across studies,…

This review describes a computational approach for modeling the development of speech motor control in infants. We address the development of two levels of control: articulation of individual speech sounds (defined here as phonemes, syllables, or words for which there is an optimized motor program) and production of sound sequences such as phrases…

Purpose: Children progress from making grapheme-phoneme connections to making grapho-syllabic connections before whole-word connections during reading development (Ehri, 2005a). More is known about the development of grapheme--phoneme connections than is known about grapho-syllabic connections. Therefore, we explored the trajectory of syllable use…

Purpose: Smoothed cepstral peak prominence (CPPS) and harmonics-to-noise ratio (HNR) are acoustic measures related to the periodicity, harmonicity, and noise components of an acoustic signal. To date, there is little evidence about the advantages of CPPS over HNR in voice diagnostics. Recent studies indicate that voice fundamental frequency (F0)…

Purpose: The purpose of this article was to validate a novel acoustic analysis of oral diadochokinesis (DDK) in assessing bulbar motor involvement in amyotrophic lateral sclerosis (ALS). Method: An automated acoustic DDK analysis was developed, which filtered out the voice features and extracted the envelope of the acoustic waveform reflecting the…

Language has a rhythmic structure, but little is known about the mechanisms that underlie how it is planned. Traditional models of language production assume that metrical and segmental planning occur independently and in parallel (Roelofs & Meyer, 1998). We test this claim in three experiments. In Experiment 1, participants completed an…

Recent findings have revealed that very preterm neonates already show the typical brain responses to place of articulation changes in stop consonants, but data on their sensitivity to other types of phonetic changes remain scarce. Here, we examined the impact of 7-8 weeks of extra-uterine life on the automatic processing of syllables in 20 healthy…

Purpose: To better understand the role of tongue visibility in speech, this study compared the spatiotemporal patterns of silent versus audible speech for lingual consonants of American English. Kinematic data were obtained for articulatory features assumed to be visually salient, including tongue movement (anterior displacement and midsagittal…

The extent of quantitative and qualitative differences in phonological development between bilingual children and their monolingual counterparts remains unresolved, especially with regard to typologically-related languages. The current study used a comparative research design to examine the phonological skills of preschool children speaking Polish…

Subjective impressions of speech delivery in Autism Spectrum Disorder (ASD) as monotonic or over-precise are widespread but still lack robust acoustic evidence. This study provides a detailed acoustic characterization of the specificities of speech in individuals with ASD using an extensive sample of speech data, from the production of narratives…