Increasing Motivation Increases Intelligibility Benefits of Perceptual Training in Dysarthria.

Purpose: Perceptual training offers a promising, listener-targeted option for improving intelligibility of dysarthric speech. Cognitive resources are required for learning, and theoretical models of listening effort and engagement account for a role of listener motivation in allocation of such resources. Here, we manipulate training instructions to enhance motivation to test the hypothesis that increased motivation increases the intelligibility benefits of perceptual training.

Perceptual Learning of Dysarthria in Adolescence.

Purpose: As evidenced by perceptual learning studies involving adult listeners and speakers with dysarthria, adaptation to dysarthric speech is driven by signal predictability (speaker property) and a flexible speech perception system (listener property). Here, we extend adaptation investigations to adolescent populations and examine whether adult and adolescent listeners can learn to better understand an adolescent speaker with dysarthria.

Method: Classified by developmental stage, adult ( = 42) and adolescent ( = 40) listeners completed a three-phase perceptual learning protocol (pretest, familiarization, and posttest).

Vowel Acoustics as Predictors of Speech Intelligibility in Dysarthria.

Purpose: This study sought to determine if alternative vowel space area (VSA) measures (i.e., novel trajectory-based measures: vowel space hull area and vowel space density) predicted speech intelligibility to the same extent as two traditional vowel measures (i.

Cognitive Predictors of Perception and Adaptation to Dysarthric Speech in Young Adult Listeners.

Purpose: Although recruitment of cognitive-linguistic resources to support dysarthric speech perception and adaptation is presumed by theoretical accounts of effortful listening and supported by cross-disciplinary empirical findings, prospective relationships have received limited attention in the disordered speech literature. This study aimed to examine the predictive relationships between cognitive-linguistic parameters and intelligibility outcomes associated with familiarization with dysarthric speech in young adult listeners.

Method: A cohort of 156 listener participants between the ages of 18 and 50 years completed a three-phase perceptual training protocol (pretest, training, and posttest) with one of three speakers with dysarthria.

The Reliability and Validity of Speech-Language Pathologists' Estimations of Intelligibility in Dysarthria.

This study examined the reliability and validity of speech-language pathologists' (SLP) estimations of speech intelligibility in dysarthria, including a visual analog scale (VAS) method and a percent estimation method commonly used in clinical settings. Speech samples from 20 speakers with dysarthria of varying etiologies were used to collect orthographic transcriptions from naïve listeners n=70 and VAS ratings and percent estimations of intelligibility from SLPs n=21. Intra- and interrater reliability for the two SLP intelligibility measures were evaluated, and the relationship between these measures was assessed.

A Perceptual Learning Approach for Dysarthria Remediation: An Updated Review.

Purpose Early studies of perceptual learning of dysarthric speech, those summarized in Borrie, McAuliffe, and Liss (2012), yielded preliminary evidence that listeners could to better understand the speech of a person with dysarthria, revealing a potentially promising avenue for future intelligibility interventions. Since then, a programmatic body of research grounded in models of perceptual processing has unfolded. The current review provides an updated account of the state of the evidence in this area and offers direction for moving this work toward clinical implementation.

A Clinical Advantage: Experience Informs Recognition and Adaptation to a Novel Talker With Dysarthria.

Purpose Perceptual training paradigms, which leverage the mechanism of perceptual learning, show that naïve listeners, those with no prior experience with dysarthria, benefit from explicit familiarization with a talker with dysarthria. It is theorized that familiarization affords listeners an opportunity to acquire distributional knowledge of the degraded speech signal. Here, we extend investigations to clinically experienced listeners, speech-language pathologists (SLPs), and advance models of listener recognition and adaptation to dysarthric speech.

Generalized Learning of Dysarthric Speech Between Male and Female Talkers.

Purpose Perceptual training is a listener-targeted means for improving intelligibility of dysarthric speech. Recent work has shown that training with one talker generalizes to a novel talker of the same sex and that the magnitude of benefit is maximized when the talkers are perceptually similar. The current study expands previous findings by investigating whether perceptual training effects generalize between talkers of different sex.

When Additional Training Isn't Enough: Further Evidence That Unpredictable Speech Inhibits Adaptation.

Purpose Robust improvements in intelligibility following familiarization, a listener-targeted perceptual training paradigm, have been revealed for talkers diagnosed with spastic, ataxic, and hypokinetic dysarthria but not for talkers with hyperkinetic dysarthria. While the theoretical explanation for the lack of intelligibility improvement following training with hyperkinetic talkers is that there is insufficient distributional regularity in the speech signals to support perceptual adaptation, it could simply be that the standard training protocol was inadequate to facilitate learning of the unpredictable talker. In a pair of experiments, we addressed this possible alternate explanation by modifying the levels of exposure and feedback provided by the perceptual training protocol to offer listeners a more robust training experience.

Regularity Matters: Unpredictable Speech Degradation Inhibits Adaptation to Dysarthric Speech.

Purpose Listener-targeted perceptual training paradigms, which leverage the mechanism of perceptual learning, show strong promise for improving intelligibility in dysarthria, offsetting the communicative burden from the speaker onto the listener. Theoretical models of perceptual learning underscore the importance of acoustic regularity (i.e.

The Effects of Speech Compression Algorithms on the Intelligibility of Two Individuals With Dysarthric Speech.

Purpose Telemedicine, used to offset disparities in access to speech-language therapy, relies on technology that utilizes compression algorithms to transmit signals efficiently. These algorithms have been thoroughly evaluated on healthy speech; however, the effects of compression algorithms on the intelligibility of disordered speech have not been adequately explored. Method This case study assessed acoustic and perceptual effects of resampling and speech compression (i.

Understanding dysrhythmic speech: When rhythm does not matter and learning does not happen.

A positive relationship between rhythm perception and improved understanding of a naturally dysrhythmic speech signal, ataxic dysarthria, has been previously reported [Borrie, Lansford, and Barrett. (2017). J.

Effects of Familiarization on Intelligibility of Dysarthric Speech in Older Adults With and Without Hearing Loss.

Purpose: Familiarization tasks offer a promising platform for listener-targeted remediation of intelligibility disorders associated with dysarthria. To date, the body of work demonstrating improved understanding of dysarthric speech following a familiarization experience has been carried out on younger adults. The primary purpose of the present study was to examine the intelligibility effects of familiarization in older adults.

Receptive Vocabulary, Cognitive Flexibility, and Inhibitory Control Differentially Predict Older and Younger Adults' Success Perceiving Speech by Talkers With Dysarthria.

Purpose: Previous research has demonstrated equivocal findings related to the effect of listener age on intelligibility ratings of dysarthric speech. The aim of the present study was to investigate the mechanisms that support younger and older adults' perception of speech by talkers with dysarthria.

Method: Younger and older adults identified words in phrases produced by talkers with dysarthria.

Predicting Intelligibility Gains in Dysarthria Through Automated Speech Feature Analysis.

Purpose: Behavioral speech modifications have variable effects on the intelligibility of speakers with dysarthria. In the companion article, a significant relationship was found between measures of speakers' baseline speech and their intelligibility gains following cues to speak louder and reduce rate (Fletcher, McAuliffe, Lansford, Sinex, & Liss, 2017). This study reexamines these features and assesses whether automated acoustic assessments can also be used to predict intelligibility gains.

Generalized Adaptation to Dysarthric Speech.

Purpose: Generalization of perceptual learning has received limited attention in listener adaptation studies with dysarthric speech. This study investigated whether adaptation to a talker with dysarthria could be predicted by the nature of the listener's prior familiarization experience, specifically similarity of perceptual features, and level of intelligibility.

Method: Following an intelligibility pretest involving a talker with ataxic dysarthria, 160 listeners were familiarized with 1 of 7 talkers with dysarthria-who differed from the test talker in terms of perceptual similarity (same, similar, dissimilar) and level of intelligibility (low, mid, high)-or a talker with no neurological impairment (control).

Predicting Intelligibility Gains in Individuals With Dysarthria From Baseline Speech Features.

Purpose: Across the treatment literature, behavioral speech modifications have produced variable intelligibility changes in speakers with dysarthria. This study is the first of two articles exploring whether measurements of baseline speech features can predict speakers' responses to these modifications.

Methods: Fifty speakers (7 older individuals and 43 speakers with dysarthria) read a standard passage in habitual, loud, and slow speaking modes.

Cognitive factors as predictors of accented speech perception for younger and older adults.

Though some studies suggest that older adults are not differentially impacted by foreign-accented speech relative to younger adults, other studies indicate that older adults are poorer at perceiving foreign-accented speech than younger adults. The present study sought, first, to clarify the extent to which older and younger adults differed in their perception of foreign-accented speech. The secondary aim was to elucidate the extent to which the cognitive mechanisms supporting accented speech perception differ for older and younger adults.

Listeners' attitudes toward accented talkers uniquely predicts accented speech perception.

Listeners' sensitivity to indexical information influences their ability to perceive and remember speech, but it is less clear if listeners' subjective ratings of talker characteristics also impact speech perception ability. The present experiment tested the increase in variance accounted for by listeners' ratings of foreign accented talkers' manner of speaking and of the talkers themselves beyond the variance already accounted for by listeners' age, executive function, and hearing thresholds. Adding listeners' ratings significantly improved model fit, indicating that listeners' subjective experience of talker impacts speech perception accuracy along with objective listener characteristics such as hearing thresholds or executive function.

Rhythm Perception and Its Role in Perception and Learning of Dysrhythmic Speech.

Purpose: The perception of rhythm cues plays an important role in recognizing spoken language, especially in adverse listening conditions. Indeed, this has been shown to hold true even when the rhythm cues themselves are dysrhythmic. This study investigates whether expertise in rhythm perception provides a processing advantage for perception (initial intelligibility) and learning (intelligibility improvement) of naturally dysrhythmic speech, dysarthria.

Assessing Vowel Centralization in Dysarthria: A Comparison of Methods.

Purpose: The strength of the relationship between vowel centralization measures and perceptual ratings of dysarthria severity has varied considerably across reports. This article evaluates methods of acoustic-perceptual analysis to determine whether procedural changes can strengthen the association between these measures.

Method: Sixty-one speakers (17 healthy individuals and 44 speakers with dysarthria) read a standard passage.

Modeling listener perception of speaker similarity in dysarthria.

The current investigation contributes to a perceptual similarity-based approach to dysarthria characterization by utilizing an innovative statistical approach, multinomial logistic regression with sparsity constraints, to identify acoustic features underlying each listener's impressions of speaker similarity. The data-driven approach also permitted an examination of the effect of clinical experience on listeners' impressions of similarity. Listeners, irrespective of level of clinical experience, were found to rely on similar acoustic features during the perceptual sorting task, known as free classification.

Use of Crowdsourcing to Assess the Ecological Validity of Perceptual-Training Paradigms in Dysarthria.

Purpose: It has been documented in laboratory settings that familiarizing listeners with dysarthric speech improves intelligibility of that speech. If these findings can be replicated in real-world settings, the ability to improve communicative function by focusing on communication partners has major implications for extending clinical practice in dysarthria rehabilitation. An important step toward development of a listener-targeted treatment approach requires establishment of its ecological validity.

The relationship between speech segment duration and vowel centralization in a group of older speakers.

This study examined the relationship between average vowel duration and spectral vowel quality across a group of 149 New Zealand English speakers aged 65 to 90 yr. The primary intent was to determine whether participants who had a natural tendency to speak slowly would also produce more spectrally distinct vowel segments. As a secondary aim, this study investigated whether advancing age exhibited a measurable effect on vowel quality and vowel durations within the group.

Free-classification of perceptually similar speakers with dysarthria.

Purpose: In this investigation, the construct of perceptual similarity was explored in the dysarthrias. Specifically, we employed an auditory free-classification task to determine whether listeners could cluster speakers by perceptual similarity, whether the clusters mapped to acoustic metrics, and whether the clusters were constrained by dysarthria subtype diagnosis.

Method: Twenty-three listeners blinded to speakers' medical and dysarthria subtype diagnoses participated.