Fluency Status Research Articles

Comparison of performance of automatic recognizers for stutters in speech trained with event or interval markers.

Automatic recognition of stutters (ARS) from speech recordings can facilitate objective assessment and intervention for people who stutter. However, the performance of ARS systems may depend on how the speech data are segmented and labelled for training and testing. This study compared two segmentation methods: event-based, which delimits speech segments by their fluency status, and interval-based, which uses fixed-length segments regardless of fluency. Machine learning models were trained and evaluated on interval-based and event-based stuttered speech corpora. The models used acoustic and linguistic features extracted from the speech signal and the transcriptions generated by a state-of-the-art automatic speech recognition system. The results showed that event-based segmentation led to better ARS performance than interval-based segmentation, as measured by the area under the curve (AUC) of the receiver operating characteristic. The results suggest differences in the quality and quantity of the data because of segmentation method. The inclusion of linguistic features improved the detection of whole-word repetitions, but not other types of stutters. The findings suggest that event-based segmentation is more suitable for ARS than interval-based segmentation, as it preserves the exact boundaries and types of stutters. The linguistic features provide useful information for separating supra-lexical disfluencies from fluent speech but may not capture the acoustic characteristics of stutters. Future work should explore more robust and diverse features, as well as larger and more representative datasets, for developing effective ARS systems.

Stuttering in individuals with Down syndrome: a systematic review of earlier research.

The main objective of this systematic review was to synthesize the evidence on the occurrence and characteristics of stuttering in individuals with Down syndrome and thus contribute knowledge about stuttering in this population. Group studies reporting outcome measures of stuttering were included. Studies with participants who were preselected based on their fluency status were excluded. We searched the Eric, PsychInfo, Medline, Scopus, and Web of Science Core Collection databases on 3rd January 2022 and conducted supplementary searches of the reference lists of previous reviews and the studies included in the current review, as well as relevant speech and language journals. The included studies were coded in terms of information concerning sample characteristics, measurement approaches, and stuttering-related outcomes. The appraisal tool for cross-sectional studies (AXIS) was used to evaluate study quality. We identified 14 eligible studies, with a total of 1,833 participants (mean = 131.29, standard deviation = 227.85, median = 45.5) between 3 and 58 years of age. The estimated occurrence of stuttering ranged from 2.38 to 56%, which is substantially higher than the estimated prevalence (1%) of stuttering in the general population. The results also showed that stuttering severity most often was judged to be mild-to-moderate and that individuals with Down syndrome displayed secondary behaviors when these were measured. However, little attention has been paid to investigating the potential adverse effects of stuttering for individuals with Down syndrome. We judged the quality of the evidence to be moderate-to-low. The negative evaluation was mostly due to sampling limitations that decreased the representability and generalizability of the results. Based on the high occurrence of stuttering and the potential negative effects of this condition, individuals with Down syndrome who show signs of stuttering should be referred to a speech and language pathologist for an evaluation of their need for stuttering treatment.

Children who stutter at 3 years of age: A community-based study

PurposeLack of social resources to support children who stutter may be due, in part, to the absence of epidemiological data regarding stuttering. This study investigated the proportion of three-year-old children who stutter in a city located in Hokkaido, a northern island of Japan. MethodsThe speech of individual children was assessed as part of a routine, government-conducted health care examination for 3-year-old children. The number of children screened was 2274, or 94.4% of all children in the city. The first author participated in the health care examination, and followed up all of the children who were found to stutter. ResultsAt 3 years of age, 1.41% of the children exhibited stuttering; 82.8% of these children subsequently did not exhibit stuttering six months later. Boys were 1.57 times more likely to stutter than girls, but they had only 86% of the probability of reported or observed fluency seen in girls six months later. Significantly higher probability of later fluency was observed in children who exhibited normal, rather than delayed, language development at the 1.5-year health checkup preceding the 3-year health checkup. ConclusionThe proportion of three-year-old children who stutter and fluency status 6 months later are reported for a large cohort of Japanese children in Hokkaido. Language skills at 1;6 year may potentially be a factor in natural recovery or persistence; because of limitations in our study design, this assumption requires additional study. This is the first preliminary study to determine the proportion of three-year-old children who stutter in a Japanese community.

Predicting the pattern and severity of chronic post-stroke language deficits from functionally-partitioned structural lesions.

There is an ever-increasing wealth of knowledge arising from basic cognitive and clinical neuroscience on how speech and language capabilities are organised in the brain. It is, therefore, timely to use this accumulated knowledge and expertise to address critical research challenges, including the ability to predict the pattern and level of language deficits found in aphasic patients (a third of all stroke cases). Previous studies have mainly focused on discriminating between broad aphasia dichotomies from purely anatomically-defined lesion information. In the current study, we developed and assessed a novel approach in which core language areas were mapped using principal component analysis in combination with correlational lesion mapping and the resultant ‘functionally-partitioned’ lesion maps were used to predict a battery of 21 individual test scores as well as aphasia subtype for 70 patients with chronic post-stroke aphasia. Specifically, we used lesion information to predict behavioural scores in regression models (cross-validated using 5-folds). The winning model was identified through the adjusted R2 (model fit to data) and performance in predicting holdout folds (generalisation to new cases). We also used logistic regression to predict fluent/non-fluent status and aphasia subtype. Functionally-partitioned models generally outperformed other models at predicting individual tests, fluency status and aphasia subtype.

Predicting the pattern and severity of chronic post-stroke language deficits from functionally-partitioned structural lesions.

There is an ever-increasing wealth of knowledge arising from basic cognitive and clinical neuroscience on how speech and language capabilities are organised in the brain. It is, therefore, timely to use this accumulated knowledge and expertise to address critical research challenges, including the ability to predict the pattern and level of language deficits found in aphasic patients (a third of all stroke cases). Previous studies have mainly focused on discriminating between broad aphasia dichotomies from purely anatomically-defined lesion information. In the current study, we developed and assessed a novel approach in which core language areas were mapped using principal component analysis in combination with correlational lesion mapping and the resultant 'functionally-partitioned' lesion maps were used to predict a battery of 21 individual test scores as well as aphasia subtype for 70 patients with chronic post-stroke aphasia. Specifically, we used lesion information to predict behavioural scores in regression models (cross-validated using 5-folds). The winning model was identified through the adjusted R2 (model fit to data) and performance in predicting holdout folds (generalisation to new cases). We also used logistic regression to predict fluent/non-fluent status and aphasia subtype. Functionally-partitioned models generally outperformed other models at predicting individual tests, fluency status and aphasia subtype.

Culture and listeners’ gaze responses to stuttering

It is frequently observed that listeners demonstrate gaze aversion to stuttering. This response may have profound social/communicative implications for both fluent and stuttering individuals. However, there is a lack of empirical examination of listeners' eye gaze responses to stuttering, and it is unclear whether cultural background plays a role in regulating listeners' eye gaze response to stuttering. To examine listeners' eye gaze responses to stuttering speech relative to fluent speech in three cultural groups. Eighteen African-American, 18 European-American and 18 Chinese adults were audiovisually presented with three stuttering and three fluent speech samples, when an eye-tracking device simultaneously recorded their gaze behaviours. The targets of listeners' eye gaze included four regions of interest (ROIs) on the speaker's face: eyes, nose, mouth and outside (i.e., everything else). Listeners' per cent of gaze time, gaze fixation count and average duration of gaze fixation were analysed with repeated-measures ANOVAs regarding each ROI as functions of the speaker's fluency status and listeners' cultural background. When observing stuttering speech, listeners tended to reduce gaze fixation duration on the speaker's eyes and increase their gaze time on the mouth. However, different from the two American groups, the Chinese group reduced their gaze time on the speaker's mouth. In addition, the Chinese participants' gaze behaviours were more focused on the ROI of outside, whereas the two American groups showed a similar focus on the ROIs of eyes and mouth. All groups of listeners responded to stuttering with gaze aversions mainly contributed to by a reduction in gaze fixation duration rather than gaze fixation number. This pattern of gaze aversion suggests that stuttering oppresses listeners with an emotional and/or cognitive overload. Attention shift and compensation strategies for speech signal degradation may also account for listeners' gaze responses to stuttering. Cultural differences in eye gaze responses to stuttering were observed mainly between Chinese and American listeners.

Speech Disfluency in School-Age Children’s Conversational and Narrative Discourse

This study was designed to (a) compare the speech fluency of school-age children who do and do not stutter (CWS and CWNS, respectively) within 2 standard diagnostic speaking contexts (conversation and narration) while also controlling for speaking topic, and (b) examine the extent to which children's performance on such discourse tasks is affected by age. Participants were 44 school-age children who were divided evenly into four groups, depending on their age (older, younger) and fluency status (CWS, CWNS). Children conversed with an examiner about a series of pictures and then told a story about the same pictures. School-age CWS produced more instances of atypical (stuttering-like) disfluencies in the narrative context than in the conversational context. Younger school-age children produced more instances of typical (nonstuttering-like) disfluencies in the conversational sample than did older school-age children. Age did not affect the frequency of children's stuttering-like disfluencies in either the conversational or the narrative contexts. These findings suggest that narration may offer a relatively efficient way of eliciting stuttering-like disfluencies during the assessment of stuttering. Thus, when assessing children to determine if they do or do not stutter, this type of sample should be considered in addition to the standard conversational sample.