Changes in speech intelligibility and acoustic distinctiveness along a speech rate continuum in Parkinson’s disease

Asking a person to speak slowly is a common technique in speech therapy for people with Parkinson’s disease (PD). Slowed speaking rates are thought to bring about changes in speech production that make it easier for people with speech impairments associated with PD to be understood, but this is not always the case. Furthermore, research suggests that using faster speech does not necessarily lead to decreases in speech intelligibility for some people with PD. Most studies of rate modification in PD have only included one or two rate adjustments to investigate the relationship between speech rate, intelligibility, and acoustic aspects of speech production. The present study adds to this literature and expands it by eliciting a broader range of speech rates than has previously been studied in order to provide a comprehensive description of changes along such a continuum. Two groups of people with PD and documented speech changes participated: 22 receiving standard pharmaceutical intervention, and 12 who additionally had undergone deep brain stimulation surgery (DBS), a common surgical treatment for PD. DBS is often associated with further speech impairment, but it is unknown to what extent these individuals may benefit from speech rate adjustments. Younger and older healthy control groups were also included. All participants were asked to modify their speech rate along a seven-step continuum from very slow to very fast while reading words, sentences, and responding to prompts. Naïve listeners later heard these speech samples and were asked to either transcribe or rate what they heard. Results indicated different patterns of speech changes across groups, rates, and tasks. Sentence reading and conversational speech were rated as being more intelligible at slow rates, and less intelligible at fast rates. All modified rates were found to negatively impact speech sound identification during a novel carrier phrase task. Slower speech was overall associated with greater acoustic contrast and variability, lower intensity, and higher voice quality. Differences in acoustic speech adjustments across the groups and speech rates emerged, however, in particular for the DBS group. Findings pointed to a complex relationship between speech rate modifications, acoustic distinctiveness, and intelligibility

Structured heterogeneity in Scottish stops over the 20th Century

How and why speakers differ in the phonetic implementation of phonological contrasts, and the relationship of this ‘structured heterogeneity’ to language change, has been a key focus over fifty years of variationist sociolinguistics. In phonetics, interest has recently grown in uncovering ‘structured variability’—how speakers can differ greatly in phonetic realization in nonrandom ways—as part of the long-standing goal of understanding variability in speech. The English stop voicing contrast, which combines extensive phonetic variability with phonological stability, provides an ideal setting for an approach to understanding structured variation in the sounds of a community’s language that illuminates both synchrony and diachrony. This article examines the voicing contrast in a vernacular dialect (Glasgow Scots) in spontaneous speech, focusing on individual speaker variability within and across cues, including over time. Speakers differ greatly in the use of each of three phonetic cues to the contrast, while reliably using each one to differentiate voiced and voiceless stops. Interspeaker variability is highly structured: speakers lie along a continuum of use of each cue, as well as correlated use of two cues—voice onset time and closure voicing—along a single axis. Diachronic change occurs along this axis, toward a more aspiration-based and less voicing-based phonetic realization of the contrast, suggesting an important connection between synchronic and diachronic speaker variation

Structured heterogeneity in Scottish stops over the twentieth 20th century

How and why speakers differ in the phonetic implementation of phonological contrasts, and the relationship of this ‘structured heterogeneity’ to language change, has been a key focus over 50 years of variationist sociolinguistics. In phonetics, interest has recently grown in uncovering ‘structured variability’—how speakers can differ greatly in phonetic realization in non-random ways—as part of the longstanding goal of understanding variability in speech. The English stop voicing contrast, which combines extensive phonetic variability with phonological stability, provides an ideal setting for an approach to understanding structured variation in the sounds of a community’s language which illuminates both synchrony and diachrony. This paper examines the voicing contrast in a vernacular dialect (Glasgow Scots) in spontaneous speech, focusing on individual speaker variability within and across cues, including over time. Speakers differ greatly in the use of each of three phonetic cues to the contrast, while reliably using each one to differentiate voiced and voiceless stops. Interspeaker variability is highly structured: speakers lie along a continuum of use of each cue, as well as correlated use of two cues—VOT and closure voicing—along a single axis. Diachronic change occurs along this axis, towards a more aspiration-based and less voicing-based phonetic realization of the contrast, suggesting an important connection between synchronic and diachronic speaker variation

Recommendations for enterovirus diagnostics and characterisation within and beyond Europe.

Enteroviruses (EV) can cause severe neurological and respiratory infections, and occasionally lead to devastating outbreaks as previously demonstrated with EV-A71 and EV-D68 in Europe. However, these infections are still often underdiagnosed and EV typing data is not currently collected at European level. In order to improve EV diagnostics, collate data on severe EV infections and monitor the circulation of EV types, we have established European non-polio enterovirus network (ENPEN). First task of this cross-border network has been to ensure prompt and adequate diagnosis of these infections in Europe, and hence we present recommendations for non-polio EV detection and typing based on the consensus view of this multidisciplinary team including experts from over 20 European countries. We recommend that respiratory and stool samples in addition to cerebrospinal fluid (CSF) and blood samples are submitted for EV testing from patients with suspected neurological infections. This is vital since viruses like EV-D68 are rarely detectable in CSF or stool samples. Furthermore, reverse transcriptase PCR (RT-PCR) targeting the 5'noncoding regions (5'NCR) should be used for diagnosis of EVs due to their sensitivity, specificity and short turnaround time. Sequencing of the VP1 capsid protein gene is recommended for EV typing; EV typing cannot be based on the 5'NCR sequences due to frequent recombination events and should not rely on virus isolation. Effective and standardized laboratory diagnostics and characterisation of circulating virus strains are the first step towards effective and continuous surveillance activities, which in turn will be used to provide better estimation on EV disease burden

Acoustic and perceptual impact of face masks on speech: A scoping review.

During the COVID-19 pandemic, personal protective equipment such as facial masks and coverings were mandated all over the globe to protect against the virus. Although the primary aim of wearing face masks is to protect against viral transmission, they pose a potential burden on communication. The purpose of this scoping review was to identify the state of the evidence of the effect of facial coverings on acoustic and perceptual speech outcomes. The scoping review followed the framework created by Arksey & O'Malley (2005) and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines (PRISMA-ScR; Tricco et al., 2018). The search was completed in May 2021 across the following databases: PubMed, EMBASE, PsycINFO, Web of Science, and Google Scholar. A total of 3,846 records were retrieved from the database search. Following the removal of duplicates, 3,479 remained for the title/abstract screen and 149 were selected for the full-text review. Of these, 52 were included in the final review and relevant data were extracted. The 52 articles included in the final review consisted of; 11 studied perceptual outcomes only, 16 studied acoustic outcomes only, and 14 studied both perceptual and acoustic outcomes. 13 of these investigated acoustic features that could be used for mask classification. Although the findings varied from article to article, many trends stood out. Many articles revealed that face masks act as a low pass filter, dampening sounds at higher frequencies; however, the frequency range and the degree of attenuation varied based on face mask type. All but five articles that reported on perceptual outcomes showed a common trend that wearing a face mask was associated with poorer speech intelligibility. The findings of the scoping review provided evidence that facial coverings negatively impacted speech intelligibility, which is likely due to a combination of auditory and visual cue degradation. Due to the continued prevalence of mask use, how facial coverings affect a wider variety of speaker populations, such as those with communication impairments, and strategies for overcoming communication challenges should be explored

Examining Factors Influencing the Viability of Automatic Acoustic Analysis of Child Speech

Heterogeneous child speech was force-aligned to investigate whether (a) manipulating specific parameters could improve alignment accuracy and (b) forced alignment could be used to replicate published results on acoustic characteristics of /s/ production by children. Method: In Part 1, child speech from 2 corpora was force-aligned with a trainable aligner (Prosodylab-Aligner) under different conditions that systematically manipulated input training data and the type of transcription used. Alignment accuracy was determined by comparing hand and automatic alignments as to how often they overlapped (%-Match) and absolute differences in duration and boundary placements. Using mixed-effects regression, accuracy was modeled as a function of alignment conditions, as well as segment and child age. In Part 2, forced alignments derived from a subset of the alignment conditions in Part 1 were used to extract spectral center of gravity of /s/ productions from young children. These findings were compared to published results that used manual alignments of the same data. [...

Effects of Multi-talker Noise on the Acoustics of Voiceless Stop Consonants in Parkinson\u27s Disease

This study examined the effect of increased speech intensity on stop consonant acoustics in Parkinson’s disease (PD). Acoustic analyses focused on measures of spirantization, voicing during closure, stop closure durations, and voice onset time. Ten individuals with Parkinson’s disease and ten age-matched controls were audio recorded while they read aloud words from the Distinctive Features Differences Test (DFD) during two conditions: no noise and 65 dB of multi-talker background noise. When compared to controls, the participants with PD had values that approached a significant difference for the measures related to greater percent voicing into closure (p=0.074), lower mean syllable intensity (p=0.069) and greater spirantization ratio (p=0.094). When compared to the no noise condition, the 65 dB multi-talker noise condition was associated with significant changes in voice onset time (VOT), syllable intensity, spirantization ratio and other measures. In addition, the place of stop consonant production had a significant effect on measures of closure duration, VOT, spectral skewness and other measures. These preliminary findings suggest that additional studies of the effect of changes in speech intensity on stop production in PD are warranted. The results of the present study identified several acoustic measures of stop production that may be useful in future evaluations of treatment outcome in PD

Effects of Multi-talker Noise on the Acoustics of Voiceless Stop Consonants in Parkinson's Disease

This study examined the effect of increased speech intensity on stop consonant acoustics in Parkinson’s disease (PD). Acoustic analyses focused on measures of spirantization, voicing during closure, stop closure durations, and voice onset time. Ten individuals with Parkinson’s disease and ten age-matched controls were audio recorded while they read aloud words from the Distinctive Features Differences Test (DFD) during two conditions: no noise and 65 dB of multi-talker background noise. When compared to controls, the participants with PD had values that approached a significant difference for the measures related to greater percent voicing into closure (p=0.074), lower mean syllable intensity (p=0.069) and greater spirantization ratio (p=0.094). When compared to the no noise condition, the 65 dB multi-talker noise condition was associated with significant changes in voice onset time (VOT), syllable intensity, spirantization ratio and other measures. In addition, the place of stop consonant production had a significant effect on measures of closure duration, VOT, spectral skewness and other measures. These preliminary findings suggest that additional studies of the effect of changes in speech intensity on stop production in PD are warranted. The results of the present study identified several acoustic measures of stop production that may be useful in future evaluations of treatment outcome in PD.This study examined the effect of increased speech intensity on stop consonant acoustics in Parkinson’s disease (PD). Acoustic analyses focused on measures of spirantization, voicing during closure, stop closure durations, and voice onset time. Ten individuals with Parkinson’s disease and ten age-matched controls were audio recorded while they read aloud words from the Distinctive Features Differences Test (DFD) during two conditions: no noise and 65 dB of multi-talker background noise. When compared to controls, the participants with PD had values that approached a significant difference for the measures related to greater percent voicing into closure (p=0.074), lower mean syllable intensity (p=0.069) and greater spirantization ratio (p=0.094). When compared to the no noise condition, the 65 dB multi-talker noise condition was associated with significant changes in voice onset time (VOT), syllable intensity, spirantization ratio and other measures. In addition, the place of stop consonant production had a significant effect on measures of closure duration, VOT, spectral skewness and other measures. These preliminary findings suggest that additional studies of the effect of changes in speech intensity on stop production in PD are warranted. The results of the present study identified several acoustic measures of stop production that may be useful in future evaluations of treatment outcome in PD

STN-DBS parameter optimization for speech in PD (Knowles et al., 2018)

<div><b>Purpose:</b> The settings of 3 electrical stimulation parameters were adjusted in 12 speakers with Parkinson’s disease (PD) with deep brain stimulation of the subthalamic nucleus (STN-DBS) to examine their effects on vowel acoustics and speech intelligibility.</div><div><b>Method: </b>Participants were tested under permutations of low, mid, and high STN-DBS frequency, voltage, and pulse width settings. At each session, participants recited a sentence. Acoustic characteristics of vowel production were extracted, and naive listeners provided estimates of speech intelligibility.</div><div><b>Results:</b> Overall, lower-frequency STN-DBS stimulation (60 Hz) was found to lead to improvements in intelligibility and acoustic vowel expansion. An interaction between speaker sex and STN-DBS stimulation was found for vowel measures. The combination of low frequency, mid to high voltage, and low to mid pulse width led to optimal speech outcomes; however, these settings did not demonstrate significant speech outcome differences compared with the standard clinical STN-DBS settings, likely due to substantial individual variability.</div><div><b>Conclusions: </b>Although lower-frequency STN-DBS stimulation was found to yield consistent improvements in speech outcomes, it was not found to necessarily lead to the best speech outcomes for all participants. Nevertheless, frequency may serve as a starting point to explore settings that will optimize an individual’s speech outcomes following STN-DBS surgery.</div><div><br></div><div><b>Supplemental Material S1. </b>Estimated pairwise differences for speech intelligibility (%) from the final model.</div><div><b><br></b></div><div><b>Supplemental Material S2. </b>Estimated pairwise differences for four-vowel articulation index (VAI) from the final model.</div><div><br></div><div><b>Supplemental Material S3. </b>Estimated pairwise differences for F2 transition extent (Hz) from the final model.</div><div><br></div><div>Knowles, T., Adams, S., Abeyesekera, A., Mancinelli, C., Gilmore, G., & Jog, M. (2018). Deep brain stimulation of the subthalamic nucleus parameter optimization for vowel acoustics and speech intelligibility in Parkinson’s disease. <i>Journal of Speech, Language, and Hearing Research, 61, </i>510–524<i>.</i> https://doi.org/10.1044/2017_JSLHR-S-17-0157</div

Predictive language comprehension in Parkinson's disease.

Verb and action knowledge deficits are reported in persons with Parkinson's disease (PD), even in the absence of dementia or mild cognitive impairment. However, the impact of these deficits on combinatorial semantic processing is less well understood. Following on previous verb and action knowledge findings, we tested the hypothesis that PD impairs the ability to integrate event-based thematic fit information during online sentence processing. Specifically, we anticipated persons with PD with age-typical cognitive abilities would perform more poorly than healthy controls during a visual world paradigm task requiring participants to predict a target object constrained by the thematic fit of the agent-verb combination. Twenty-four PD and 24 healthy age-matched participants completed comprehensive neuropsychological assessments. We recorded participants' eye movements as they heard predictive sentences (The fisherman rocks the boat) alongside target, agent-related, verb-related, and unrelated images. We tested effects of group (PD/control) on gaze using growth curve models. There were no significant differences between PD and control participants, suggesting that PD participants successfully and rapidly use combinatory thematic fit information to predict upcoming language. Baseline sentences with no predictive information (e.g., Look at the drum) confirmed that groups showed equivalent sentence processing and eye movement patterns. Additionally, we conducted an exploratory analysis contrasting PD and controls' performance on low-motion-content versus high-motion-content verbs. This analysis revealed fewer predictive fixations in high-motion sentences only for healthy older adults. PD participants may adapt to their disease by relying on spared, non-action-simulation-based language processing mechanisms, although this conclusion is speculative, as the analyses of high- vs. low-motion items was highly limited by the study design. These findings provide novel evidence that individuals with PD match healthy adults in their ability to use verb meaning to predict upcoming nouns despite previous findings of verb semantic impairment in PD across a variety of tasks