Clear Speech Variants: An Investigation of Intelligibility and Speaker Effort in Speakers With Parkinson's Disease

Stronger Together: A Qualitative Exploration of Social Connectedness in Parkinson's Disease in the Digital Era

PURPOSE

Social isolation is a common consequence of Parkinson's disease (PD), and social prescribing has become a crucial aspect for fostering well-being in this population. In fact, group work has been shown to improve levels of social connectedness in older adults across different domains. Increased technology use in older adults may also contribute to increased social connections, especially since the COVID-19 pandemic. Still, the impact of digital use on social connectedness remains to be further explored in individuals with PD. Therefore, the purpose of this study was to examine the perceptions of social connectedness in relation with group-based activities and use of digital technologies in this population.

METHOD

Ten individuals with PD participated in focus groups. Transcripts of the video-recorded groups were analyzed qualitatively using thematic analysis.

RESULTS

The three constructed themes not only revealed changes and challenges in social connectedness but also underscored the power of family and new relationships established through PD. Results also highlighted the overall positive impact of current digital technologies, although the view on telehealth per se was multifaceted.

CONCLUSIONS

Referrals for group rehabilitation programs can enhance social connectedness in individuals with PD through fostering new social connections and community building. Hence, group rehabilitation programs should be viewed as a form of social prescribing. The use of digital technologies should be further explored as a means to maximize social engagements in this population.

The Impact of Clear and Loud Speech Cues on Acoustic and Perceptual Features of Speech Production in Adolescents With Down Syndrome

PURPOSE

There are few evidence-based speech interventions designed to alter speech production in a way that ultimately results in increased speech intelligibility in adolescents with Down syndrome (DS). The primary purpose of this study was to examine the impact of clear and loud speech cues on acoustic and perceptual features of speech production in adolescents with DS.

METHOD

Eight adolescents diagnosed with DS repeated sentences of varying lengths in three conditions: habitual, big mouth (i.e., clear speech), and strong voice (i.e., loud speech). Four hundred eighty adult listeners (20 listeners per adolescent per condition) provided orthographic transcriptions of adolescent's speech, which were used to calculate intelligibility scores. Acoustic measures of speech rate, articulation rate, proportion of time spent pausing, vocal intensity, and fundamental frequency were calculated for each sentence.

RESULTS

The big mouth condition resulted in significantly increased intelligibility, slowed speech and articulation rates, increased pauses, increased vocal intensity, and increased fundamental frequency. The strong voice condition resulted in significantly increased vocal intensity and fundamental frequency, but no other changes. Speech rate was the only variable that explained any of the variance in intelligibility.

CONCLUSIONS

Adolescents with DS respond differently to clear and loud speech cues. In particular, clear speech cues resulted in significant increases in intelligibility, but loud speech cues did not. Clear speech cues hold promise as an intervention strategy for adolescents with DS.

Acoustic and Kinematic Predictors of Intelligibility and Articulatory Precision in Parkinson's Disease

PURPOSE

This study investigated relationships within and between perceptual, acoustic, and kinematic measures in speakers with and without dysarthria due to Parkinson's disease (PD) across different clarity conditions. Additionally, the study assessed the predictive capabilities of selected acoustic and kinematic measures for intelligibility and articulatory precision ratings.

METHOD

Forty participants, comprising 22 with PD and 18 controls, read three phrases aloud using conversational, less clear, and more clear speaking conditions. Acoustic measures and their theoretical kinematic parallel measures (i.e., acoustic and kinematic distance and vowel space area [VSA]; second formant frequency [F2] slope and kinematic speed) were obtained from the diphthong /aɪ/ and selected vowels in the sentences. A total of 368 listeners from crowdsourcing provided ratings for intelligibility and articulatory precision. The research questions were examined using correlations and linear mixed-effects models.

RESULTS

Intelligibility and articulatory precision ratings were highly correlated across all speakers. Acoustic and kinematic distance, as well as F2 slope and kinematic speed, showed moderately positive correlations. In contrast, acoustic and kinematic VSA exhibited no correlation. Among all measures, acoustic VSA and kinematic distance were robust predictors of both intelligibility and articulatory precision ratings, but they were stronger predictors of articulatory precision.

CONCLUSIONS

The findings highlight the importance of measurement selection when examining cross-domain relationships. Additionally, they support the use of behavioral modifications aimed at eliciting larger articulatory gestures to improve intelligibility in individuals with dysarthria due to PD.

OPEN SCIENCE FORM

https://doi.org/10.23641/asha.27011281.

Effect of clear speech on acoustic measures of dysprosody in Parkinson disease for different reading tasks

PURPOSE

The purpose of the study was to determine the effect of clear speech instruction on acoustic measures of dysprosody between reading passages of differing linguistic content for speakers with and without Parkinson Disease (PD).

METHOD

Ten speakers with PD and 10 controls served as participants and read five simple and three standard reading stimuli twice. First, speakers read habitually and then following clear speech instruction. Acoustic measures of fundamental frequency variation (semitone standard deviation, STSD), articulation rate, and between-complex pause durations were calculated.

RESULT

Results indicated speakers with PD exhibited less fundamental frequency variation than controls across reading stimuli and instructions. All speakers exhibited lower STSD and longer between-complex pause durations for the standard compared to simple reading stimuli. For clear speech, all speakers reduced articulation rate and increased between-complex pause durations in both simple and standard reading stimuli. However, speakers with PD exhibited a significantly less robust reduction in articulation rate for clear speech than control speakers for all reading stimuli.

CONCLUSION

Linguistic content of reading stimuli contributes to differences in fundamental frequency variation and pause duration for all speakers. All speakers reduced articulation rate for clear speech compared to habitual instruction, but speakers with PD did so to a lesser extent than controls. Linguistic content of reading stimuli to examine dysprosody in PD should be considered for clinical application.

Contributions of Speech Timing and Articulatory Precision to Listener Perceptions of Intelligibility and Naturalness in Parkinson's Disease

PURPOSE

Parkinson's disease (PD) results in hypokinetic dysarthria in as many as 90% of cases. Among the most distinctive features of hypokinetic dysarthria are atypical timing and articulatory imprecision in speech production. Here, we examined the contributions of perceived speech timing typicality and articulatory precision, both on their own and while controlling for the other, on intelligibility and naturalness in speakers with PD.

METHOD

Twenty speakers with PD and four healthy older adults read aloud the first paragraph of the Rainbow Passage. Twenty inexperienced listeners with typical hearing listened to these recordings and rated intelligibility, naturalness, timing typicality, and articulatory precision using separate visual analog scales. Ratings were averaged across listeners and entered into linear regression models with intelligibility and naturalness as dependent variables and timing typicality and articulatory precision as independent variables in each.

RESULTS

Articulatory precision, but not timing typicality, was positively correlated with intelligibility on its own, but neither was associated with intelligibility after accounting for the other. Both timing typicality and articulatory precision were positively correlated with naturalness on their own as well as after controlling for the other variable.

CONCLUSION

These results contribute to the overall understanding of speech factors associated with intelligibility and naturalness in speakers with PD and indicate that considering the unique contributions of related perceptual constructs may provide more information than bivariate relationships alone.

Speech Amplification Device Usage for the Management of Hypophonia: A Survey of Speech-Language Pathologists

PURPOSE

The purpose of this study was to survey speech-language pathologists (SLPs) who assess and treat people with Parkinson's disease (PD) to gather insights into their decision making regarding their use or potential use of speech amplification technology for the management of hypophonia.

METHOD

A total of 111 SLPs who were currently practicing in the United States or Canada and had experience working with clients with PD for at least 2 years completed an anonymous Qualtrics survey. Questions were designed to probe the following areas: (a) degree of familiarity with amplification devices as a form of treatment for PD, (b) attitudes and perceptions of the implementation of these devices for PD, and (c) factors that influence the clinical decision to prescribe such devices.

RESULTS

Most participants (75; 71%) reported they had considered prescribing a device to at least one client with PD. When asked at which stages of speech or voice impairment they would consider the use of an amplification device for clients with PD, the most common response was for clients with moderate or severe hypophonia who were not stimulable for louder speech. However, 36 (32%) respondents indicated they would also consider an amplification device for clients who were stimulable for louder speech with severe hypophonia. When asked to rank the most important factors they would weigh when considering the prescription of an amplification device, they ranked the client's preference and comfort level as the most important consideration.

CONCLUSION

This study provides valuable clinical insights regarding how SLPs can approach utilizing speech amplification devices in the therapy environment.

The Effects of Interactive Context on Acoustic Characteristics of Speech in People With Dysarthria: A Preliminary Study

PURPOSE

The current study compared temporal and spectral acoustic contrast between vowel segments produced by speakers with dysarthria across three speech tasks-interactive, solo habitual, and solo clear.

METHOD

Nine speakers with dysarthria secondary to amyotrophic lateral sclerosis participated in the study. Each speaker was paired with a typical interlocutor over videoconferencing software. The speakers produced the vowels /i, ɪ, ɛ, æ/ in /h/-vowel-/d/ words. For the solo tasks, speakers read the stimuli aloud in both their habitual and clear speaking styles. For the interactive task, speakers produced a target stimulus for their interlocutor to select among the four possibilities. We measured the duration difference between long and short vowels, as well as the F1/F2 Euclidean distance between adjacent vowels, and also determined how well the vowels could be classified based on their acoustic characteristics.

RESULTS

Temporal contrast between long and short vowels was higher in the interactive task than in both solo tasks. Spectral distance between adjacent vowel pairs was also higher for some pairs in the interactive task than the habitual speech task. Finally, vowel classification accuracy was highest in the interactive task.

CONCLUSIONS

Overall, we found evidence that individuals with dysarthria produced vowels with greater acoustic contrast in structured interactions than they did in solo tasks. Furthermore, the speech adjustments they made to the vowel segments differed from those observed in solo speech.

Improving Perceptual Speech Ratings: The Effects of Auditory Training on Judgments of Dysarthric Speech

PURPOSE

Auditory training has been shown to reduce rater variability in perceptual voice assessment. Because rater variability is also a central issue in the auditory-perceptual assessment of dysarthria, this study sought to determine if training produces a meaningful change in rater reliability, criterion validity, and scaling magnitude of four features: overall speech impairment, articulatory imprecision, monotony, and slow rate.

METHOD

Forty-four nonexperts randomized to training and nontraining listener groups completed a pretest and posttest. Only the former group underwent auditory training between pre- and posttests. For both testing and training, listeners rated samples from speakers with amyotrophic lateral sclerosis (ALS), speakers with Parkinson's disease (PD), and neurologically healthy control speakers using separate visual analog scales (VASs) for each of the four features. Intraclass correlation coefficients were used to compare inter- and intrarater reliability between pre- and posttest for both listener groups. For criterion validity, severity ratings from the two nonexpert listener groups were compared to those of two experienced listeners for all four features. To determine changes in scaling magnitude, raw VAS scores for each feature were compared from pre- to posttest within the two nonexpert listener groups. Scaling changes were also compared between the two listener groups for the pre- and posttest conditions.

RESULTS AND CONCLUSIONS

In the training group, a meaningful improvement in interrater reliability was observed for some features in all three speaker groups, but not in the nontraining group. In contrast, for intrarater reliability, in the nontraining group, a meaningful improvement was observed for many features in all three speaker groups, but only for PD monotony and slow rate in the training group. All ratings from the nonexpert listeners were valid except for monotony. Raw VAS scores did not meaningfully change from pre- to posttest for any of the features, but there was a trend toward lower scores posttraining, mainly for the ALS samples. Modifications to the auditory training paradigm to further improve reliability and validity, along with future goals for optimizing training, are discussed.

Effect of Face Masks and Speech Style on Speech Intelligibility and Listener Effort in Parkinson's Disease

PURPOSE

The aim of this study was to quantify the combined effects of face masks and effortful speech styles on listener intelligibility and perceived listener effort in talkers with and without Parkinson's disease (PD).

METHOD

Ten people with PD and 10 healthy, older controls read aloud sentences in two face mask and three speech style conditions. Masks included no mask and KN95 masks. Speech styles included habitual, clear, and loud. Listener participants were tasked with listening to each sentence mixed with background noise and then transcribing what they heard and rating how effortful it was to understand. Listener accuracy and effort were each modeled as a function of speaker group, face mask, and speech style using mixed-effects regression models.

RESULTS

Listeners were less accurate and reported greater listening effort for the PD group and for the mask condition. Listeners were more accurate and reported less effort when listening to clear and loud compared to habitual speech. Listener accuracy and listener effort were strongly negatively correlated across all conditions. Face masks were also associated with a steeper decline in speech intelligibility and an increase in listener effort for talkers with PD.

DISCUSSION

Face masks resulted in steeper speech intelligibility decline for talkers with PD compared to controls. Speaking more loudly or more clearly when wearing a face mask improved intelligibility for talkers with PD compared to habitual speech, and both speech styles resulted in speech intelligibility levels that approximated talkers' baseline intelligibility levels without a mask.

Pareto-Optimized Non-Negative Matrix Factorization Approach to the Cleaning of Alaryngeal Speech Signals

The problem of cleaning impaired speech is crucial for various applications such as speech recognition, telecommunication, and assistive technologies. In this paper, we propose a novel approach that combines Pareto-optimized deep learning with non-negative matrix factorization (NMF) to effectively reduce noise in impaired speech signals while preserving the quality of the desired speech. Our method begins by calculating the spectrogram of a noisy voice clip and extracting frequency statistics. A threshold is then determined based on the desired noise sensitivity, and a noise-to-signal mask is computed. This mask is smoothed to avoid abrupt transitions in noise levels, and the modified spectrogram is obtained by applying the smoothed mask to the signal spectrogram. We then employ a Pareto-optimized NMF to decompose the modified spectrogram into basis functions and corresponding weights, which are used to reconstruct the clean speech spectrogram. The final noise-reduced waveform is obtained by inverting the clean speech spectrogram. Our proposed method achieves a balance between various objectives, such as noise suppression, speech quality preservation, and computational efficiency, by leveraging Pareto optimization in the deep learning model. The experimental results demonstrate the effectiveness of our approach in cleaning alaryngeal speech signals, making it a promising solution for various real-world applications.