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Speech rate is a basic characteristic of language production, which affects the speaker's intelligibility and communication efficiency. Various speech disorders, including persistent developmental stuttering, present altered speech rate. Specifically, adults who stutter (AWS) typically exhibit a slower speech rate compared to fluent speakers. Evidence from imaging studies suggests that the cerebellum contributes to the paced production of speech. People who stutter show structural and functional abnormalities in the cerebellum. However, the involvement of the cerebellar pathways in controlling speech rate remains unexplored. Here, we assess the association of the cerebellar peduncles with speech rate in AWS and control speakers. Diffusion MRI and speech-rate data were collected in 42 participants (23 AWS, 19 controls). We used deterministic tractography with Automatic Fiber segmentation and Quantification (AFQ) to identify the superior, middle, and inferior cerebellar peduncles (SCP, MCP, ICP) bilaterally, and quantified fractional anisotropy (FA) and mean diffusivity (MD) along each tract. No significant differences were observed between AWS and controls in the diffusivity values of the cerebellar peduncles. However, AWS demonstrated a significant negative association between speech rate and FA within the left ICP, a major cerebellar pathway that transmits sensory feedback signals from the olivary nucleus into the cerebellum. The involvement of the ICP in controlling speech production in AWS is compatible with the view that stuttering stems from hyperactive speech monitoring, where even minor deviations from the speech plan are considered as errors. In conclusion, our findings suggest a plausible neural mechanism for speech rate reduction observed in AWS.

Purpose: This study is a preliminary attempt to evaluate a new speech fluency measure, the Speech Efficiency Score (SES), in comparison with subjective stuttering severity rating scales and stuttered syllable counts (%SS)., Methods: 277 listeners (92 naïve, 39 speech-language pathology (SLP) students, 124 practicing SLPs, and 22 SLPs who specialize in stuttering) evaluated short recordings of speech on an 11-point scale. Recordings were obtained from 56 adults, of whom 20 were people who stutter, 16 were people who stutter who were using fluency-shaping techniques, and 20 were speakers who do not stutter. In addition, %SS and the SES measure were obtained for each recording., Results: The four listener groups rated stuttering severity similarly, with no statistically significant between-group differences. Listeners' responses on the stuttering severity rating scales and the SES yielded significant differences between all three speaker groups. The %SS measure yielded a significant difference only between the stuttering group and the other two groups but not between the fluency-shaping and the control groups. A very strong positive correlation was found between the SES and the subjective stuttering-severity rating scales (r = 0.92). The correlation between %SS and the perceptual evaluation, as well as the correlation between %SS and the SES, were lower, though they still reached significance., Conclusions: Results suggest that speech efficiency scores, which are based on a time-domain analysis, closely match subjective stuttering severity ratings and could ultimately provide a more objective way to measure speech fluency., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: Speech rate convergence has been reported previously as a phenomenon in which one's speech rate is influenced by his/her partner's speech rate. This phenomenon has been demonstrated in artificial settings, and to some extent, in mother-child interactions. The purpose of this study was to explore speech rate adjustment in a quasi-natural adult-adult conversation., Methods: An A-B-A-B paradigm was used, in which ten adults conversed on a given topic with two experimenters. Speech rates of both communication partners were measured., Results: Participants significantly reduced their speech rate, in response to the experimenters' reduction in speech rate. However, the participants' reduction in speech rate was significantly smaller than the experimenters' reduction in speech rate. In addition, during the controlled slow speech rate, the participants' speech rate correlated negatively with that of the experimenters'., Conclusion: Results suggest that speech rate convergence is a non-linear phenomenon, and may be affected by various linguistic as well as communicational factors. From a clinical perspective, the results support the use of the modeling strategy in speech therapy, as a means to facilitate a reduction in clients' speech rate., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: Fluent speech production relies on the coordinated processing of multiple brain regions. This highlights the role of neural pathways that connect distinct brain regions in producing fluent speech. Here, we aim to investigate the role of the white matter pathways in persistent developmental stuttering (PDS), where speech fluency is disrupted., Methods: We use diffusion weighted imaging and tractography to compare the white matter properties between adults who do and do not stutter. We compare the diffusion properties along 18 major cerebral white matter pathways. We complement the analysis with an overview of the methodology and a roadmap of the pathways implicated in PDS according to the existing literature., Results: We report differences in the microstructural properties of the anterior callosum, the right inferior longitudinal fasciculus and the right cingulum in people who stutter compared with fluent controls., Conclusions: Persistent developmental stuttering is consistently associated with differences in bilateral distributed networks. We review evidence showing that PDS involves differences in bilateral dorsal fronto-temporal and fronto-parietal pathways, in callosal pathways, in several motor pathways and in basal ganglia connections. This entails an important role for long range white matter pathways in this disorder. Using a wide-lens analysis, we demonstrate differences in additional, right hemispheric pathways, which go beyond the replicable findings in the literature. This suggests that the affected circuits may extend beyond the known language and motor pathways., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Adults who stutter can learn to control and improve their speech fluency by modifying their speaking rate. Existing speech therapy technologies can assist this practice by monitoring speaking rate and providing feedback to the patient, but cannot provide an accurate, quantitative measurement of speaking rate. Moreover, most technologies are too complex and costly to be used for home practice. We developed an algorithm and a smartphone application that monitor a patient's speaking rate in real time and provide user-friendly feedback to both patient and therapist. Our speaking rate computation is performed by a phoneme counting algorithm which implements spectral transition measure extraction to estimate phoneme boundaries. The algorithm is implemented in real time in a mobile application that presents its results in a user-friendly interface. The application incorporates two modes: one provides the patient with visual feedback of his/her speech rate for self-practice and another provides the speech therapist with recordings, speech rate analysis and tools to manage the patient's practice. The algorithm's phoneme counting accuracy was validated on ten healthy subjects who read a paragraph at slow, normal and fast paces, and was compared to manual counting of speech experts. Test-retest and intra-counter reliability were assessed. Preliminary results indicate differences of -4% to 11% between automatic and human phoneme counting. Differences were largest for slow speech. The application can thus provide reliable, user-friendly, real-time feedback for speaking rate control practice., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Persistent developmental stuttering is a speech disorder that affects an individual's ability to fluently produce speech. While the disorder mainly manifests in situations that require language production, it is still unclear whether persistent developmental stuttering is indeed a language impairment, and if so, which language stream is implicated in people who stutter. In this study, we take a neuroanatomical approach to this question by examining the structural properties of the dorsal and ventral language pathways in adults who stutter (AWS) and fluent controls. We use diffusion magnetic resonance imaging and individualized tract identification to extract white matter volumes and diffusion properties of these tracts in samples of adults who do and do not stutter. We further quantify diffusion properties at multiple points along the tract and examine group differences within these diffusivity profiles. Our results show differences in the dorsal, but not in the ventral, language-related tracts. Specifically, AWS show reduced volume of the left dorsal stream, as well as lower anisotropy in the right dorsal stream. These data provide neuroanatomical support for the view that stuttering involves an impairment in the bidirectional mapping between auditory and articulatory cortices supported by the dorsal pathways, not in lexical access and semantic aspects of language processing which are thought to rely more heavily on the left ventral pathways., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Developmental stuttering is a speech disorder that severely limits one's ability to communicate. White matter anomalies were reported in stuttering, but their functional significance is unclear. We analyzed the relation between white matter properties and speech fluency in adults who stutter (AWS). We used diffusion tensor imaging with tract-based spatial statistics, and examined group differences as well as correlations with behavioral fluency measures. We detected a region in the anterior corpus callosum with significantly lower fractional anisotropy in AWS relative to controls. Within the AWS group, reduced anisotropy in that region is associated with reduced fluency. A statistically significant interaction was found between group and age in two additional regions: the left Rolandic operculum and the left posterior corpus callosum. Our findings suggest that anterior callosal anomaly in stuttering may represent a maladaptive reduction in interhemispheric inhibition, possibly leading to a disadvantageous recruitment of right frontal cortex in speech production., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Identified the acoustic features of the vowels produced by Hebrew speakers differing in age and sex. Ninety speakers were recorded. Vowels were presented in a nonword context that was placed in a meaningful Hebrew sentence. Results are discussed. (Author/VWL)

This study aimed to quantify articulation rate among Hebrew speaking children and adolescents across a wide age range, and to assess whether age-related differences vary according to metric. One hundred and forty children, in seven age groups, participated in this cross-sectional study. All children were recorded during conversation and a picture description task, and articulation rate was measured using three metrics: word per minute (WPM), syllable per second (SPS) and phone per second (PPS). A significant increase in articulation rate was observed with age. Rate measurements during conversation were significantly faster than in picture description, and no gender differences were found. In general, the SPS and PPS metrics yielded equivalent results, which were different from those obtained with the WPM metric. Articulation rate among normally fluent children and adolescents increased with age. Furthermore, an increase in rate was evident after the age of 13 years. [ABSTRACT FROM PUBLISHER]