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Purpose: The goal of this study was to determine the relationship between the perceptual measure of speech naturalness and objective measures of pitch, loudness, and rate control as a potential tool for assessment of ataxic dysarthria., Method: Twenty-seven participants with ataxia and 29 age- and sex-matched control participants completed the pitch glide and loudness step tasks drawn from the Frenchay Dysarthria Assessment-Second Edition (FDA-2) in addition to speech diadochokinetic (DDK) tasks. First, group differences were compared for pitch variability in the pitch glide task, loudness variability in the loudness step task, and syllable duration and speech rate in the DDK task. Then, these acoustic measures were compared with previously collected ratings of speech naturalness by speech-language pathology graduate students., Results: Robust group differences were measured for pitch variability and both DDK syllable duration and speech rate, indicating that the ataxia group had greater pitch variability, longer DDK syllable duration, and slower DDK speech rate than the control group. No group differences were measured for loudness variability. There were robust relationships between speech naturalness and pitch variability, DDK syllable duration, and DDK speech rate, but not for loudness variability., Conclusions: Objective acoustic measures of pitch variability in the FDA-2 pitch glide task and syllable duration and speech rate in the DDK task can be used to validate perceptual measures of speech naturalness. Overall, speech-language pathologists can incorporate both perceptual measures of speech naturalness and acoustic measures of pitch variability and DDK performance for a comprehensive evaluation of ataxic dysarthria.

Purpose: Although relatively precise control over the extent and rate of fundamental frequency (f o ) modulation may be needed for optimal production of vibrato, the role of auditory feedback in controlling vibrato is not well understood. Previous studies altered the gain and timing of auditory feedback in singers producing vibrato and showed inconsistent effects on the extent and rate of f o modulation, which may have been related to small sample sizes or limited analyses. Therefore, the purpose of this study was to further investigate whether the gain or timing of auditory feedback impacts control of vibrato in a larger sample of speakers and with advanced statistical analyses., Method: Ten classically-trained singers produced sustained vowels with vibrato while their auditory feedback was masked with pink noise or multi-talker babble to reduce the gain of their auditory feedback and while their auditory feedback was delayed by about 200 or 300 milliseconds to alter the timing of their auditory feedback. Acoustical analyses measured changes in the extent and rate of f o modulation in the masked and delayed trials relative to control trials. Bayesian modeling was used to analyze the effects of noise-masked, babble-masked, and delayed auditory feedback on the extent and rate of f o modulation., Results: There was compelling evidence that noise masking increased the extent of f o modulation, and babble masking increased the variability in the rate of f o modulation (ie, jitter of f o modulation). Masked auditory feedback did not affect the average rate of f o modulation. Delayed auditory feedback did not affect the extent, rate, or jitter of f o modulation., Conclusions: The current study demonstrated that reducing the gain of the auditory feedback with noise masking increased the extent of f o modulation but did not affect the average rate of f o modulation in classically-trained singers producing vibrato. Reducing the gain of the auditory feedback with babble masking and altering the timing of auditory feedback with imposed delays did not affect the average extent or rate of f o modulation. However, babble masking increased the jitter of f o modulation rate, which suggests that modulated auditory feedback may affect the periodicity of f o modulation from one modulation cycle to the next. These findings clarify the role of auditory feedback in controlling vibrato and may inform the current reflex-resonance models of vibrato., (Copyright © 2022 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: This case study measured how well the Lee Silverman Voice Treatment (LSVT) improved vocal features, intelligibility, and communicative effectiveness for a multilingual participant with hypokinetic-hyperkinetic dysarthria secondary to suspected progressive supranuclear palsy. LSVT treatment was chosen for the participant due to the strengths and deficits he presented with prior to treatment, and for the anticipated challenges in treatment that may arise from the presence of multilingualism and impaired cognitive functioning., Methods: A multilingual patient in their 60's (English, Spanish, and French) with hypokinetic-hyperkinetic dysarthria secondary to suspected progressive supranuclear palsy completed the standard treatment sessions for LSVT. Assessment measures were taken at baseline, immediately post-treatment, and three-months post-treatment., Results: Improvements were measured in vocal quality, vocal loudness, intelligibility, and communicative effectiveness immediately post-treatment. Three months post-treatment, improvements in vocal quality and intelligibility were maintained., Conclusion: This case study illustrates that LSVT may be a beneficial treatment for complex clients who are multilingual and present with complex comorbidities and cognitive deficits. LSVT resulted in some meaningful changes in vocal quality, intelligibility, and communicative effectiveness for this individual. Clinicians who work with complex patients may wish to consider the theoretical underpinnings of LSVT, client profile, areas of client need, and ability and desire to complete an intensive treatment program to determine if trialing LSVT is appropriate. The use of LSVT with complex clients may yield positive outcomes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Sebestyen, Hilger and Kleiber.)

Purpose: The purpose of this study was to identify potential barriers to speech pathology referral in ataxia, as well as potential factors influencing satisfaction with speech pathology and communicative participation., Method: An online survey study included questions about participant demographics, referral and access to speech pathology, satisfaction with speech pathology, and communicative participation via the Communicative Participation Item Bank (CPIB)., Results: We analysed 118 eligible responses from individuals with ataxia. Results from Bayesian regression models indicated that the overall referral rate to speech pathology was 64% for the respondents with a speech impairment, predicted by lower income, less education, and greater self-perceived speech severity. Additionally, sex, self-perceived speech severity, and length of speech impairment predicted more restricted communicative participation. For the respondents who were referred for speech pathology, overall satisfaction with speech pathology was neutral to high but most individuals reported little to no improvement in their speech., Conclusion: Referral rate to speech pathology was low given that dysarthria and dysphagia are highly likely to occur in ataxia. Considerations should be made for perceived speech severity, sex, and length of speech impairment in evaluating communicative participation. Lastly, there is a vital need for evidence-based treatment for ataxic dysarthria.

The purpose of this analysis was to document intelligibility and naturalness in ataxia, a neurological condition that results from cerebellar damage. The cerebellum is important for normal speech production to scale and coordinate articulatory and laryngeal movements. The disruption of these cerebellar mechanisms has unique implications for how intelligibility and naturalness are affected in ataxia. The results of research on speech in ataxia have important clinical implications for assessment and treatment of individuals with ataxic dysarthria. Speech samples from 27 participants with ataxia and 28 age- and sex-matched control participants were assessed by nine speech-language pathology graduate students for intelligibility and naturalness. Intelligibility was measured as the percentage of words transcribed correctly, and naturalness was assessed as a subjective rating on a seven-point interval scale. Both intra- and inter-rater reliability were moderate to high for both intelligibility and naturalness. Speech intelligibility and naturalness were robustly decreased in the ataxia group compared to the control group; however, the difference was greater for measures of speech naturalness. There were robust relationships among dysarthria severity, length of diagnosis, and speech naturalness in speakers with ataxia, but there were no other robust effects for age, sex, or impact on quality of life for intelligibility or naturalness. Speech naturalness was more impaired than intelligibility in speakers with ataxia. Impaired naturalness can have debilitating consequences for communicative participation, effectiveness, and quality of life. Assessment and treatment for ataxic dysarthria should include aspects of prosodic control for speech naturalness., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: The purpose of this study was to investigate how classically trained singers use their auditory feedback to control fundamental frequency (f o ) during production of vocal vibrato. Two main questions were addressed: (1) Do singers produce reflexive f o responses to sudden perturbation of the f o of their auditory feedback during production of vibrato indicative of feedback control? (2) Do singers produce adaptive f o responses to repeated perturbation of the f o of their auditory feedback during production of vibrato indicative of feedback and feedforward control? In addition, one methodological question was addressed to determine if adaptive f o responses were more precisely assessed with or without an auditory cue for f o during the repeated f o perturbation paradigm., Method: Ten classically trained singers produced sustained vowels with vibrato while the f o and harmonics of their auditory feedback were suddenly perturbed by 100 cents to assess reflexive control or repeatedly perturbed by 100 cents to assess adaptive control. Half of the participants completed the repeated perturbation experiment with an auditory cue for f o , and the other half completed the experiment without an auditory cue for f o . Acoustical analyses measured changes in mean f o in response to the auditory feedback perturbations., Results: On average, participants produced compensatory responses to both sudden and repeated perturbation of the f o of their auditory feedback. The magnitude of the responses to repeated perturbations was larger than the responses to sudden perturbations. Responses were also larger in the cued, repeated f o perturbation experiment than in the uncued, repeated f o perturbation experiment., Conclusions: These findings indicate that classically-trained singers use both feedforward and feedback mechanisms to control their average f o during production of vibrato. When compared to prior studies of singers producing a steady voice, the reflexive f o responses were larger in the current study, which may indicate that the feedback control system is engaged more during production of vibrato., (Copyright © 2021 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

This study investigated the effect of semantic focus on pitch auditory feedback control in the production of phrasal prosody through an experiment using pitch-shifted auditory feedback. We hypothesized that pitch-shift responses would be mediated by semantic focus because highly informative focus types, such as corrective focus, impose more specific constraints on the prosodic form of a phrase and require greater consistency in the production of pitch excursions compared to sentences with no such focus elements. Twenty-eight participants produced sentences with and without corrective focus while their auditory feedback was briefly and unexpectedly perturbed in pitch by +/-200 cents at the start of the sentence. The magnitude and latency of the reflexive pitch-shift responses were measured as a reflection of auditory feedback control. Our results matched our prediction that corrective focus would elicit larger pitch-shift responses, supporting our hypothesis that auditory feedback control is mediated by semantic focus.

Objective: Dysphonia is a reduction in vocal quality that impacts communication and is often an early sign of a voice disorder. There is little information regarding the effects of auditory feedback control of loudness and pitch on voice quality. In this study, we used both loudness-shift and pitch-shift paradigms to study the relationship between auditory feedback control and vocal quality as measured by smoothed cepstral peak prominence (CPPS), which reflects the harmonicity of the voice signal., Study Design: Experimental, mixed design., Methods: We applied 200 ms loudness-shifts (± 0, 3, or 6 dB) and pitch-shifts (± 0, 50, and 100 cents) to auditory feedback during sustained vowel production in 25 healthy adults. We then measured CPPS before and after the loudness-shift or pitch-shift to investigate the effect of changes in auditory feedback on vocal harmonicity., Results & Conclusions: Results showed that, on average, CPPS significantly decreased between the first half of the measured segment and the last half of the segment in the absence of auditory feedback shifts, suggesting that voice quality may be reduced across longer vowels over time. Upward and downward shifts in loudness auditory feedback caused a relative increase in CPPS, indicating an improvement in vocal harmonicity, even in cases when vocal intensity was reduced. Pitch alterations had inconsistent and minimal effects. We propose that there may be a control mechanism for voice quality that increases harmonicity of the voice signal to improve voice audibility (ie, ability to be heard) in the presence of unpredictable variability in voice intensity., (Copyright © 2020 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Auditory feedback control of fundamental frequency (f o ) is modulated in a task-dependent manner. When voice pitch auditory feedback perturbations are applied in sentence versus sustained-vowel production, larger and faster vocal f o responses are measured in sentence production. This task-dependency reflects the scaling of auditory targets for pitch for the precision required in each speech task. When the range for the pitch auditory target is scaled down for precision (as in the sentence-production task), a greater degree of mismatch is detected from the feedback perturbation and a larger vocal response is measured. The purpose of this study was to determine whether auditory feedback control of vocal intensity is also modulated in a task-dependent manner similar to the control of vocal pitch. Twenty-five English speakers produced repetitions of a sentence and a sustained vowel while hearing their voice auditory feedback briefly perturbed in loudness (+/- 3 or 6 dB SPL, 200 ms duration). The resulting vocal intensity responses were measured, and response magnitudes were robustly larger in the sentence (mean: 1.96 dB) than vowel production (mean: 0.89 dB). Additionally, response magnitudes increased as a function of perturbation magnitude only in sentence production for downward perturbations but decreased in magnitude by perturbation magnitude for upward perturbations. Peak response latencies were robustly shorter in sentence (mean: 184.94 ms) than in vowel production (mean: 214.92 ms). Overall, these results support the hypothesis that auditory feedback control of pitch and loudness are modulated by task and that both pitch and loudness auditory targets are scaled for the precision required for the speaking task., (Copyright © 2022. Published by Elsevier Inc.)

Purpose In this study, we investigated how the direction and timing of a perturbation in voice pitch auditory feedback during phrasal production modulated the magnitude and latency of the pitch-shift reflex as well as the scaling of acoustic production of anticipatory intonation targets for phrasal prominence and boundary. Method Brief pitch auditory feedback perturbations (±200 cents for 200-ms duration) were applied during the production of a target phrase on the first or the second word of the phrase. To replicate previous work, we first measured the magnitude and latency of the pitch-shift reflex as a function of the direction and timing of the perturbation within the phrase. As a novel approach, we also measured the adjustment in the production of the phrase-final prominent word as a function of perturbation direction and timing by extracting the acoustic correlates of pitch, loudness, and duration. Results The pitch-shift reflex was greater in magnitude after perturbations on the first word of the phrase, replicating the results from Mandarin speakers in an American English-speaking population. Additionally, the production of the phrase-final prominent word was acoustically enhanced (lengthened vowel duration and increased intensity and fundamental frequency) after perturbations earlier in the phrase, but more so after perturbations on the first word in the phrase. Conclusion The timing of the pitch perturbation within the phrase modulated both the magnitude of the pitch-shift reflex and the production of the prominent word, supporting our hypothesis that speakers use auditory feedback to correct for immediate production errors and to scale anticipatory intonation targets during phrasal production.

Purpose: Stuttering involves a breakdown in the speech motor system. We address whether stuttering in its early stage is specific to the speech motor system or whether its impact is observable across motor systems., Method: As an extension of Olander, Smith, and Zelaznik (2010), we measured bimanual motor timing performance in 115 children: 70 children who stutter (CWS) and 45 children who do not stutter (CWNS). The children repeated the clapping task yearly for up to 5 years. We used a synchronization-continuation rhythmic timing paradigm. Two analyses were completed: a cross-sectional analysis of data from the children in the initial year of the study (ages 4;0 [years;months] to 5;11) compared clapping performance between CWS and CWNS. A second, multiyear analysis assessed clapping behavior across the ages 3;5-9;5 to examine any potential relationship between clapping performance and eventual persistence or recovery of stuttering., Results: Preschool CWS were not different from CWNS on rates of clapping or variability in interclap interval. In addition, no relationship was found between bimanual motor timing performance and eventual persistence in or recovery from stuttering. The disparity between the present findings for preschoolers and those of Olander et al. (2010) most likely arises from the smaller sample size used in the earlier study., Conclusion: From the current findings, on the basis of data from relatively large samples of stuttering and nonstuttering children tested over multiple years, we conclude that a bimanual motor timing deficit is not a core feature of early developmental stuttering.