Speech intelligibility in severe adductor spasmodic dysphonia

The Relationship Between Voice Parameters and Speech Intelligibility: A Scoping Review

OBJECTIVE

To synthesize existing evidence of the relationship between voice parameters and speech intelligibility.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Review (PRISMA-ScR) guidelines, 13 databases were searched and a manual search was conducted. A narrative synthesis of methodological quality, study characteristics, participant demographics, voice parameter categorization, and their relationship to speech intelligibility was conducted. A Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment was also performed.

RESULTS

A total of 5593 studies were retrieved, and 30 eligible studies were included in the final scoping review. The studies were given scores of 10-25 (average 16.93) out of 34 in the methodological quality assessment. Research that analyzed voice parameters related to speech intelligibility, encompassing perceptual, acoustic, and aerodynamic parameters, was included. Validated and nonvalidated perceptual voice assessments showed divergent results regarding the relationship between perceptual parameters and speech intelligibility. The relationship between acoustic parameters and speech intelligibility was found to be complex and the results were inconsistent. The limited research on aerodynamic parameters did not reach a consensus on their relationship with speech intelligibility. Studies in which listeners were not speech-language pathologists (SLPs) far outnumbered those with SLP listeners, and research conducted in English contexts significantly exceeded that in non-English contexts. The GRADE evaluation indicated that the quality of evidence varied from low to moderate.

DISCUSSION

The results for the relationship between voice parameters and intelligibility showed significant heterogeneity. Future research should consider age-related voice changes and include diverse age groups. To enhance validity and comparability, it will be necessary to report effect sizes, tool validity, inter-rater reliability, and calibration procedures. Voice assessments should account for the validation status of tools because of their potential impact on the outcomes. The linguistic context may also influence the results.

Treatment Outcome Measures for Spasmodic Dysphonia: A Systematic Review

PURPOSE

This systematic review aims to identify instruments used to evaluate treatment outcomes for people with spasmodic dysphonia.

METHODS

Electronic database (PubMed, Cochrane Library, Embase, and CINAHL) searches and hand-searching identified studies that evaluated treatment approaches for spasmodic dysphonia which included pre and post outcome data.

RESULTS

A total of 4714 articles were retrieved from searching databases; 1165 were duplicates. Titles and abstracts of 3549 were screened, with 171 being selected for full-text review. During full-text review, 101 articles were deemed suitable for inclusion. An additional 24 articles were identified as suitable for inclusion through hand-searching of reference lists. Data was extracted from 125 studies, identifying 220 outcome measures. As per the World Health Organization's International Classification of Functioning (ICF), the majority measured body functions (n = 212, 96%). Outcomes that explored communication and participation in everyday life and attitudes towards communication (ie, activity and participation domains) were infrequent (n = 8; 4%). Quality of life, a paradigm outside of the scope of the ICF, was also captured by four outcome measures. No instruments evaluating communication partners' perspectives were identified.

CONCLUSIONS

Currently there is no unified approach to the measurement of outcomes in SD treatment research. Development and implementation of a core outcome set is recommended to facilitate improved understanding of the efficacy of current and new treatment options.

Automated Creak Differentiates Adductor Laryngeal Dystonia and Muscle Tension Dysphonia

OBJECTIVE

The purpose of this study was to determine whether automated estimates of vocal creak would differentiate speakers with adductor laryngeal dystonia (AdLD) from speakers with muscle tension dysphonia (MTD) and speakers without voice disorders.

METHODS

Sixteen speakers with AdLD, sixteen speakers with MTD, and sixteen speakers without voice disorders were recorded in a quiet environment reading aloud a standard paragraph. An open-source creak detector was used to calculate the percentage of creak (% creak) in each of the speaker's six recorded sentences.

RESULTS

A Kruskal-Wallis one-way analysis of variance revealed a statistically significant effect of group on the % creak with a large effect size. Pairwise Wilcoxon tests revealed a statistically significant difference in % creak between speakers with AdLD and controls as well as between speakers with AdLD and MTD. Receiver operating characteristic curve analyses indicated that % creak differentiated AdLD from both controls and speakers with MTD with high sensitivity and specificity (area under the curve statistics of 0.94 and 0.86, respectively).

CONCLUSION

Percentage of creak as calculated by an automated creak detector may be useful as a quantitative indicator of AdLD, demonstrating the potential for use as a screening tool or to aid in a differential diagnosis.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2687-2694, 2023.

Spectral Aggregate of the High-Passed Fundamental Frequency and Its Relationship to the Primary Acoustic Features of Adductor Laryngeal Dystonia

OBJECTIVE

Currently, no clinically feasible objective measures exist that are specific to the signs of adductor laryngeal dystonia (LD), deterring effective diagnosis and treatment. This project sought to establish concurrent validity of a new automated acoustic outcome measure, designed to be specific to adductor laryngeal dystonia (AdLD): the spectral aggregate of the high-passed fundamental frequency contour (SAHf o).

METHOD

Twenty speakers with AdLD read voiced phoneme-loaded (more symptomatic) and voiceless phoneme-loaded (less symptomatic) sentences. LD discontinuities (defined as phonatory breaks, frequency shifts, and creak), the acoustic ramifications of laryngeal spasms, were manually identified. The frequency content of the f o contour was examined as a function of time, and content above 1000 Hz was summed to automatically calculate SAHf o. Multiple linear regression analysis was applied to SAHf o based on LD discontinuities and sentence type (voiced or voiceless phoneme-loaded).

RESULTS

The regression model accounted for 41.1% of the variance in SAHf o. Both the LD discontinuities and sentence type were statistically related to SAHf o.

CONCLUSION

Results of this study provide evidence of concurrent validity. SAHf o is an automatic outcome measure specific to acoustic signs of AdLD that may be useful to track treatment progress.

The Effects of Dysphonic Voice on Speech Intelligibility in Cantonese-Speaking Adults

Purpose This study aims to investigate the effects of dysphonic voice on speech intelligibility in Cantonese-speaking adults. Method Speech recordings from three speakers with dysphonia secondary to phonotrauma and three speakers with healthy voices were presented to 30 healthy listeners (15 men and 15 women; M _age = 22.7 years) under six noise conditions (signal-to-noise ratio [SNR] -10, SNR -5, SNR 0, SNR +5, SNR +10) and quiet conditions. The speech recordings were composed of sentences with five different lengths: five syllables, eight syllables, 10 syllables, 12 syllables, and 15 syllables. The effects of speaker's voice quality, background noise condition, and sentence length on speech intelligibility were examined. Speech intelligibility scores were calculated based on the listener's correct judgment of the number of syllables heard as a percentage of the total syllables in each stimulus. Results Dysphonic voices, as compared to healthy voices, were significantly more affected by background noise. Speech presented with dysphonic voices was significantly less intelligible than speech presented with healthy voices under unfavorable SNR conditions (SNR -10, SNR -5, and SNR 0 conditions). However, there was no sufficient evidence to suggest effects of sentence length on intelligibility, regardless of the speaker's voice quality or the level of background noise. Conclusions This study provides empirical data on the impacts of dysphonic voice on speech intelligibility in Cantonese speakers. The findings highlight the importance of educating the public about the impacts of voice quality and background noise on speech intelligibility and the potential of compensatory strategies that specifically address these barriers. Supplemental Material https://doi.org/10.23641/asha.13335926.

Hey Siri: How Effective are Common Voice Recognition Systems at Recognizing Dysphonic Voices?

OBJECTIVES/HYPOTHESIS

Interaction with voice recognition systems, such as Siri™ and Alexa™, is an increasingly important part of everyday life. Patients with voice disorders may have difficulty with this technology, leading to frustration and reduction in quality of life. This study evaluates the ability of common voice recognition systems to transcribe dysphonic voices.

STUDY DESIGN

Retrospective evaluation of "Rainbow Passage" voice samples from patients with and without voice disorders.

METHODS

Participants with (n = 30) and without (n = 23) voice disorders were recorded reading the "Rainbow Passage". Recordings were played at standardized intensity and distance-to-dictation programs on Apple iPhone 6S™, Apple iPhone 11 Pro™, and Google Voice™. Word recognition scores were calculated as the proportion of correctly transcribed words. Word recognition scores were compared to auditory-perceptual and acoustic measures.

RESULTS

Mean word recognition scores for participants with and without voice disorders were, respectively, 68.6% and 91.9% for Apple iPhone 6S™ (P < .001), 71.2% and 93.7% for Apple iPhone 11 Pro™ (P < .001), and 68.7% and 93.8% for Google Voice™ (P < .001). There were strong, approximately linear associations between CAPE-V ratings of overall severity of dysphonia and word recognition score, with correlation coefficients (R² ) of 0.609 (iPhone 6S™), 0.670 (iPhone 11 Pro™), and 0.619 (Google Voice™). These relationships persisted when controlling for diagnosis, age, gender, fundamental frequency, and speech rate (P < .001 for all systems).

CONCLUSION

Common voice recognition systems function well with nondysphonic voices but are poor at accurately transcribing dysphonic voices. There was a strong negative correlation with word recognition scores and perceptual voice evaluation. As our society increasingly interfaces with automated voice recognition technology, the needs of patients with voice disorders should be considered.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1599-1607, 2021.

Effect of Dysphonia and Cognitive-Perceptual Listener Strategies on Speech Intelligibility

There is a high prevalence of dysphonia among professional voice users and the impact of the disordered voice on the speaker is well documented. However, there is minimal research on the impact of the disordered voice on the listener. Considering that professional voice users include teachers and air-traffic controllers, among others, it is imperative to determine the impact of a disordered voice on the listener. To address this, the objectives of the current study included: (1) determine whether there are differences in speech intelligibility between individuals with healthy voices and those with dysphonia; (2) understand whether cognitive-perceptual strategies increase speech intelligibility for dysphonic speakers; and (3) determine the relationship between subjective voice quality ratings and speech intelligibility. Sentence stimuli were recorded from 12 speakers with dysphonia and four age- and gender-matched typical, healthy speakers and presented to 129 healthy listeners divided into one of three strategy groups (ie, control, acknowledgement, and listener strategies). Four expert raters also completed a perceptual voice assessment using the Consensus Assessment Perceptual Evaluation of Voice for each speaker. Results indicated that dysphonic voices were significantly less intelligible than healthy voices (P ≤ 0.001) and the use of cognitive-perceptual strategies provided to the listener did not significantly improve speech intelligibility scores (P = 0.602). Using the subjective voice quality ratings, regression analysis found that breathiness was able to predict 41% of the variance associated with number of errors (P = 0.008). Overall results of the study suggest that speakers with dysphonia demonstrate reduced speech intelligibility and that providing the listener with specific strategies may not result in improved intelligibility.

The Effect of Information and Severity on Perception of Speakers With Adductor Spasmodic Dysphonia

PURPOSE

The purpose of this study was to examine the effect of severity of adductor spasmodic dysphonia (ADSD) and information about it on unfamiliar listeners' attitudes about speakers' personal characteristics, perceived vocal effort, and listener comfort on the basis of ratings of speech recordings.

METHOD

Fifteen women with ADSD and 5 controls provided speech samples. Forty-five unfamiliar listeners were randomized into 3 groups. Listeners in Group 1 received no information, listeners in Group 2 were told that some speakers had voice disorders or had no voice concerns, and listeners in Group 3 were provided diagnostic labels for each speaker and information about ADSD. Listeners then rated speech samples for attitudes, perceived vocal effort, and listener comfort.

RESULTS

Speakers with ADSD were judged significantly worse than controls for attitudes related to "social desirability" and "intellect." There was no effect of severity on "personality" attributes. However, provision of a diagnostic label resulted in significantly more favorable personality ratings than when no label was provided. Perceived vocal effort and comfort became significantly more negative as ADSD severity increased. Finally, most listener ratings were unaffected by provision of additional information about ADSD.

CONCLUSIONS

Listeners' perceptions about speakers with ADSD are difficult to change. Directions for counseling and public education need future study.

Employer Reactions to Adductor Spasmodic Dysphonia: Exploring the Influence of Symptom Severity and Disclosure of Diagnosis During a Simulated Telephone Interview

PURPOSE

The purpose of this study was to determine the influence of symptom severity and disclosure of adductor spasmodic dysphonia (ADSD) on the perceptions of human resource personnel members (HRPs) during a simulated phone interview.

METHOD

One female speaker with ADSD was recorded reading an interview script at two time points: (a) pre-BOTOX injection (severe), and (b) post-BOTOX injection (mild). Thirty-two HRPs evaluated the recording in one of the two conditions via a qualitative structured interview. HRPs gave their recommendations regarding when and how to disclose ADSD.

RESULTS

In the mild condition, no HRP perceived that the applicant had a voice disorder. Disclosure was not recommended as often, as an impairment was not initially noticed. However, 15/16 HRPs commented on the applicant's voice in the severe condition, with most suspecting she was a smoker or had lung/throat cancer. Disclosure in the severe condition was recommended more often, as it clarified symptoms that were noted at the outset.

CONCLUSIONS

Symptom severity in ADSD influences employer perceptions during the phone interview process. Incorrect assumptions may be made about applicants with severe symptoms, and apparentness of symptoms influences whether or not disclosure is recommended. Results have implications for counseling individuals with ADSD who are navigating the job interview process.

The Impact of Dysphonic Voices on Healthy Listeners: Listener Reaction Times, Speech Intelligibility, and Listener Comprehension

PURPOSE

There is currently minimal information on the impact of dysphonia secondary to phonotrauma on listeners. Considering the high incidence of voice disorders with professional voice users, it is important to understand the impact of a dysphonic voice on their audiences.

METHODS

Ninety-one healthy listeners (39 men, 52 women; mean age = 23.62 years) were presented with speech stimuli from 5 healthy speakers and 5 speakers diagnosed with dysphonia secondary to phonotrauma. Dependent variables included processing speed (reaction time [RT] ratio), speech intelligibility, and listener comprehension. Voice quality ratings were also obtained for all speakers by 3 expert listeners.

RESULTS

Statistical results showed significant differences between RT ratio and number of speech intelligibility errors between healthy and dysphonic voices. There was not a significant difference in listener comprehension errors. Multiple regression analyses showed that voice quality ratings from the Consensus Assessment Perceptual Evaluation of Voice (Kempster, Gerratt, Verdolini Abbott, Barkmeier-Kraemer, & Hillman, 2009) were able to predict RT ratio and speech intelligibility but not listener comprehension.

CONCLUSIONS

Results of the study suggest that although listeners require more time to process and have more intelligibility errors when presented with speech stimuli from speakers with dysphonia secondary to phonotrauma, listener comprehension may not be affected.

Inferring speaker attributes in adductor spasmodic dysphonia: ratings from unfamiliar listeners

PURPOSE

To determine whether unfamiliar listeners' perceptions of speakers with adductor spasmodic dysphonia (ADSD) differ from control speakers on the parameters of relative age, confidence, tearfulness, and vocal effort and are related to speaker-rated vocal effort or voice-specific quality of life.

METHOD

Twenty speakers with ADSD (including 6 speakers with ADSD plus tremor) and 20 age- and sex-matched controls provided speech recordings, completed a voice-specific quality-of-life instrument (Voice Handicap Index; Jacobson et al., 1997), and rated their own vocal effort. Twenty listeners evaluated speech samples for relative age, confidence, tearfulness, and vocal effort using rating scales.

RESULTS

Listeners judged speakers with ADSD as sounding significantly older, less confident, more tearful, and more effortful than control speakers (p < .01). Increased vocal effort was strongly associated with decreased speaker confidence (rs = .88-.89) and sounding more tearful (rs = .83-.85). Self-rated speaker effort was moderately related (rs = .45-.52) to listener impressions. Listeners' perceptions of confidence and tearfulness were also moderately associated with higher Voice Handicap Index scores (rs = .65-.70).

CONCLUSION

Unfamiliar listeners judge speakers with ADSD more negatively than control speakers, with judgments extending beyond typical clinical measures. The results have implications for counseling and understanding the psychosocial effects of ADSD.