Relationships Between Vocal Fold Adduction Patterns, Vocal Acoustic Quality, and Vocal Effort in Individuals With and Without Hyperfunctional Voice Disorders.

OBJECTIVES/HYPOTHESIS: Increased vocal effort and aberrant vocal quality are often attributed to vocal fold hyperadduction in hyperfunctional voice disorders. However, there are currently no established methods to quantify vocal fold adduction beyond subjective descriptors in this clinical population. Furthermore, relationships between vocal fold adduction patterns, vocal effort severity, and vocal quality are not well characterized. Therefore, the objectives of this study were to (1) quantify vocal fold adduction, applying a previously validated method developed for patients with vocal fold paralysis, and (2) correlate these measures with acoustic vocal quality and self-perceived measures of vocal effort severity. METHODS: A deep learning program, Automated Glottic Action Tracking using artificial Intelligence, was used to track glottic angle configurations and vocal fold adduction velocities on laryngoscopic videos across 60 laryngoscopies (20 primary muscle tension dysphonia [pMTD], 20 phonotraumatic lesions, and 20 healthy controls). Voice samples were also acquired, and cepstral peak prominence (CPP) and H1-H2 acoustic measures were used to quantify vocal quality. Participants were also asked to rate their vocal effort on a 100 mm visual analog scale. RESULTS: There were no significant group differences in glottic angle configurations or vocal fold adduction velocities, although there were trends toward increased peak vocal fold adduction velocities in patients with hyperfunctional voice disorders compared to controls. Vocal effort was significantly higher in the two hyperfunctional groups compared to controls. CPP was significantly lower in the pMTD group, but there were no group differences in acoustic parameters between any of the other groups or for H1-H2 values. CONCLUSION: Despite significantly more vocal effort reported in patients with hyperfunctional voice disorders, there were no significant group differences in vocal fold adduction patterns. These findings suggest other physiologic mechanisms may also be responsible for the symptoms and genesis of pMTD and benign vocal fold lesions.

Acoustic and Physiologic Correlates of Vocal Effort in Individuals With and Without Primary Muscle Tension Dysphonia.

OBJECTIVES: The aims of this study were to determine relationships between vocal effort and (a) acoustic correlates of vocal output and (b) supraglottic compression in individuals with primary muscle tension dysphonia (pMTD) and without voice disorders (controls) in the context of a vocal load challenge. METHOD: Twenty-six individuals with pMTD and 35 vocally healthy controls participated in a 30-min vocal load challenge. The pre- and postload relationships among self-ratings of vocal effort, various acoustic voice measures, and supraglottic compression (mediolateral and anteroposterior) were tested with multiple regression models and post hoc Pearson's correlations. Acoustic measures included cepstral peak prominence (CPP), low-to-high spectral ratio, difference in intensity between the first two harmonics, fundamental frequency, and sound pressure level (dB SPL). RESULTS: Regression models for CPP and mediolateral compression were statistically significant. Vocal effort, diagnosis of pMTD, and vocal demand were each significant variables influencing CPP measures. CPP was lower in the pMTD group across stages. There was no statistical change in CPP following the vocal load challenge within either group, but both groups had an increase in vocal effort postload. Vocal effort and diagnosis influenced the mediolateral compression model. Mediolateral compression was higher in the pMTD group across stages and had a negative relationship with vocal effort, but it did not differ after vocal loading. CONCLUSIONS: CPP and mediolateral supraglottic compression were influenced by vocal effort and diagnosis of pMTD. Increased vocal effort was associated with lower CPP, particularly after vocal load, and decreased mediolateral supraglottic compression in the pMTD group.

Relationships Among Stimulability Testing, Patient Factors, and Voice Therapy Compliance.

OBJECTIVE: Voice stimulability testing to determine voice therapy efficacy and prognosis is commonly used during the voice evaluation, but little is known about how patient factors (eg, voice diagnosis, dysphonia severity) can influence stimulability outcomes. The predictability of voice therapy success with different stimulability facilitating techniques (eg, hums, pitch glides) is also unknown. The goals of this study were to identify relationships between patient factors, voice therapy compliance, and stimulability testing. METHODS: A retrospective chart review was conducted on 50 patients who were seen for their initial voice therapy evaluation at the UT Southwestern Clinical Center for Voice Care. Chart review included documentation of the stimulability tasks that yielded/did not yield voice changes, level of stimulability, voice diagnosis, clinician-rated auditory-perceptual analysis of vocal quality, therapy attendance, and compliance with voice therapy recommendations. Statistical analysis was conducted to determine whether the types of facilitating techniques, voice diagnosis, and dysphonia severity could predict how stimulable patients were and whether any stimulability techniques could predict voice therapy attendance and compliance. RESULTS: Patients diagnosed with functional voice disorders (eg, muscle tension dysphonia) were 11 times more likely to be stimulable for voice improvements than patients with neurological voice disorders (eg, vocal fold paralysis). Patients with lower dysphonia severity were more likely to be stimulable than patients with high dysphonia severity. Specific facilitating voice tasks did not predict the level of stimulability. Stimulability level was not predictive of therapy attendance or compliance with therapy recommendations. CONCLUSIONS: Voice diagnosis and severity of dysphonia influenced stimulability levels. However, voice stimulability was not predictive of voice therapy attendance or compliance, and no specific facilitative task predicted the level of stimulability. Future investigations should focus on other means of measuring a patient's motivation for change and on the predictive power of stimulability testing on voice therapy outcomes.

Acoustic-Aerodynamic Voice Outcome Ratios Identify Changes in Vocal Function Following Vocal Fold Medialization for Unilateral Vocal Fold Paralysis.

PURPOSE: This study aimed to determine whether ratio-based measures that combine acoustic (output) and aerodynamic (input) parameters detect postoperative change in vocal function following vocal fold medialization for unilateral vocal fold paralysis. METHOD: Pre- and postoperative acoustic and aerodynamic measures were analyzed retrospectively from 149 patients who underwent vocal fold medialization for unilateral vocal fold paralysis. A 2 × 2 repeated-measures analysis of variance was conducted for each of four acoustic-aerodynamic ratios-traditional vocal efficiency (VE), sound pressure level to aerodynamic power (SPL/AP), SPL to average airflow (SPL/AFLOW), and SPL to subglottal pressure (SPL/Ps)-to investigate the main effects and interaction of treatment stage and loudness level (comfortable and loud). RESULTS: The patient group showed significant postoperative improvements in self reports of vocal function (voice-related quality of life) and clinical auditory-perceptual judgments of dysphonia (consensus auditory-perceptual evaluation of voice). Main effects for both treatment stage and loudness level were statistically significant for all measures except SPL/Ps. There were interaction effects for VE and SPL/AP, suggesting that magnitude of the treatment effect differs based on loudness. SPL/AFLOW had medium-to-large effect sizes in both loudness conditions. There were postoperative changes in SPL/Ps that were dependent on the magnitude of the reduction in AFLOW; as expected, SPL/Ps increased postoperatively in a subgroup that had large postoperative reductions in AFLOW at the comfortable loudness level. CONCLUSIONS: Acoustic-aerodynamic ratios can aid in tracking changes in vocal function following vocal fold medialization. SPL/AFLOW exhibited the largest effect size, which is expected since a reduction in abnormally high AFLOW typically accompanies the increased modulation of glottal air flow associated with successful vocal fold medialization. Future study is needed to model physiological changes in acoustic-aerodynamic voice outcome ratios across different types of voice disorders.

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.

Understanding the Use and Importance of Voice Stimulability Assessment Among Speech-Language Pathologists Who Treat Voice Disorders: An International Survey.

PURPOSE: Stimulability assessment is a common part of the voice evaluation, but little information exists about what is involved in the process, how it is measured, and how it impacts therapeutic decisions. The aim of this study was to establish the frequency, circumstances, techniques, and rationale for stimulability assessment among voice-specialized speech-language pathologists (SLPs). METHOD: An anonymized online survey was distributed to voice-specialized SLPs through email lists, online communities, and professional networks. Surveys queried clinical demographic information, respondents' definition of stimulability, importance of stimulability assessment, frequency with which stimulability assessment is performed for various patient populations, preferred facilitating techniques, importance of stimulability assessment for a variety of clinical goals, and methods of measuring voice stimulability. RESULTS: Eighty-eight responses were analyzed. All respondents perform voice stimulability assessment, with 97% considering the practice important. Stimulability assessment is completed with all voice disorders and is consistently completed with muscle tension dysphonia, phonotraumatic disorders, vocal fold mobility disorders, and presbyphonia. Ninety-one percent of the sample does not use a structured stimulability assessment protocol. All respondents felt that stimulability is, to some degree, predictive of successful voice therapy outcomes. Resonance modifications and semi-occluded vocal tract techniques were the most commonly used facilitating strategies. Respondents felt that stimulability assessment was very important for assessing patient awareness, estimating prognosis, and identifying training gestures. CONCLUSIONS: Responding voice clinicians felt that stimulability assessment is an important part of the voice evaluation. This study provides information on how stimulability assessment is being used and outlines what is needed to study its impact.

Clinical Utility of the Ratio of Sound Pressure Level to Subglottal Pressure in Patients Surgically Treated for Phonotraumatic Vocal Fold Lesions.

PURPOSE: This study aimed to determine whether a simplified, and potentially more stable, acoustic-aerodynamic voice outcome ratio (ratio of sound pressure level [SPL] to subglottal pressure) is comparable to a traditional vocal efficiency measure (ratio of acoustic power to the product of average subglottal pressure and average phonatory airflow) in terms of the ability to detect change in vocal function following surgical removal of bilateral phonotraumatic lesions. METHOD: Pre- and postoperative acoustic and aerodynamic measures were analyzed retrospectively from 75 female patients who underwent surgical removal of bilateral phonotraumatic lesions. A 2 × 2 repeated-measures analysis of variance was conducted for each of three acoustic-aerodynamic voice outcome ratios-traditional vocal efficiency, an SPL-based ratio with both airflow and subglottal pressure, and a simplified SPL-based ratio with subglottal pressure only-to investigate the main effects of treatment stage (pre- and postsurgery), loudness condition (comfortable and loud), and their interaction. Post hoc paired samples t tests were conducted for statistically significant interactions. The within-subject variability of the measures was assessed using the coefficient of variation. RESULTS: Although exhibiting an expected main effect of loudness (higher values in the loud condition), the traditional vocal efficiency ratio did not exhibit a main effect of treatment. For both SPL-based ratios, there were significant main effects of treatment stage (higher values postoperatively) and loudness condition (lower values in the loud condition). Within-subject, postoperative changes in the two SPL-based ratios moderately correlated with one another. The simplified ratio of SPL to subglottal pressure (without airflow) exhibited the least within-subject variability relative to the other two acoustic-aerodynamic ratios. CONCLUSIONS: These findings indicate that SPL-based acoustic-aerodynamic voice outcome ratios increase significantly following the surgical removal of phonotraumatic vocal fold lesions. The simplified ratio of SPL to subglottal pressure exhibits the least variability and can be easily obtained without requiring the measurement of airflow.

Amount and Characteristics of Speaking and Singing Voice Use in Vocally Healthy Female College Student Singers During a Typical Week.

OBJECTIVES: Singers, college students, and females are groups known to be at an elevated risk of developing functional/hyperfunctional voice disorders; therefore, female college students majoring in vocal performance may be at an even higher risk. To mitigate this risk, it would be helpful to know the "safe limits" for voice use that would help maintain vocal health in this vulnerable group, but there is a paucity of high-quality objective information upon which to base such limits. This study employed weeklong ambulatory voice monitoring in a large group of vocally healthy female college student singers to begin providing the types of objective data that could be used to help develop improved vocal health guidelines. METHODS: Participants included 64 vocally healthy females currently enrolled in a vocal performance or similar program at a college or university. An ambulatory voice monitor recorded neck-surface acceleration throughout a typical week. A singing classifier was applied to the data to separate singing from speech. Weeklong vocal dose measures and distributional characteristics for standard voice measures were computed separately for singing and speech, and for both types of phonation combined. RESULTS: Participants spent 6.2% of the total monitoring time speaking and 2.1% singing (with total phonation time being 8.4%). Singing had a higher fo mode, more pitch variability, higher average sound pressure level (SPL), negatively skewed SPL distributions, lower average CPP, and higher H1-H2 values than speaking. CONCLUSIONS: These results provide a basis for beginning to establish vocal health guidelines for female students enrolled in college-level vocal performance programs and for future studies of the types of voice disorders that are common in this group. Results also demonstrate the potential value that ambulatory voice monitoring may have in helping to objectively identify vocal behaviors that could contribute to voice problems in this population.

Relationships Among Personality, Daily Speaking Voice Use, and Phonotrauma in Adult Female Singers.

PURPOSE: This study sought to determine whether personality traits related to extraversion and impulsivity are more strongly associated with singers with nodules compared to vocally healthy singers and to understand the relationship between personality and the types of daily speaking voice use. METHOD: Weeklong ambulatory voice recordings and personality inventories were obtained for 47 female singers with nodules and 47 vocally healthy female singers. Paired t tests investigated trait differences between groups. Relationships between traits and weeklong speaking voice measures (vocal dose, sound pressure level [SPL], neck surface acceleration magnitude [NSAM], fundamental frequency, cepstral peak prominence [CPP], and the ratio of the first two harmonic magnitudes [H 1 -H 2]) were examined using pairwise Pearson r coefficients. Multiple regressions were performed to estimate voice parameters that correlated with two or more traits. RESULTS: Singers with nodules scored higher on the Social Potency scale (reflecting a tendency toward social dominance) and lower on the Control scale (reflecting impulsivity) compared to the vocally healthy singers. In vocally healthy singers, vocal dose measures were positively correlated with a combination of Wellbeing (i.e., happiness) and Social Potency, mean SPL was positively correlated with Wellbeing, SPL variability was positively correlated with Social Potency and negatively with Harm Avoidance, and CPP mean was positively correlated with Wellbeing. Singers with nodules had a negative correlation between NSAM skewness and Social Potency. Both groups had negative correlations between H 1 -H 2 mean and Social Potency and Social Closeness. CONCLUSIONS: Singers with nodules are more socially dominant and impulsive than vocally healthy singers. Personality traits are related to daily speaking voice use, particularly in vocally healthy singers. Individuals with higher levels of traits related to happiness and social dominance and lower Harm Avoidance tended to speak more, with higher laryngeal forces, with more SPL variability, and with more pressed glottal closure, which could increase risk of phonotrauma.

Psychometric Analysis of an Ecological Vocal Effort Scale in Individuals With and Without Vocal Hyperfunction During Activities of Daily Living.

Objective The purpose of this study was to examine the psychometric properties of an ecological vocal effort scale linked to a voicing task. Method Thirty-eight patients with nodules, 18 patients with muscle tension dysphonia, and 45 vocally healthy control individuals participated in a week of ambulatory voice monitoring. A global vocal status question was asked hourly throughout the day. Participants produced a vowel-consonant-vowel syllable string and rated the vocal effort needed to produce the task on a visual analog scale. Test-retest reliability was calculated for a subset using the intraclass correlation coefficient, ICC(A, 1). Construct validity was assessed by (a) comparing the weeklong vocal effort ratings between the patient and control groups and (b) comparing weeklong vocal effort ratings before and after voice rehabilitation in a subset of 25 patients. Cohen's d, the standard error of measurement (SEM), and the minimal detectable change (MDC) assessed sensitivity. The minimal clinically important difference (MCID) assessed responsiveness. Results Test-retest reliability was excellent, ICC(A, 1) = .96. Weeklong mean effort was statistically higher in the patients than in controls (d = 1.62) and lower after voice rehabilitation (d = 1.75), supporting construct validity and sensitivity. SEM was 4.14, MDC was 11.47, and MCID was 9.74. Since the MCID was within the error of the measure, we must rely upon the MDC to detect real changes in ecological vocal effort. Conclusion The ecological vocal effort scale offers a reliable, valid, and sensitive method of monitoring vocal effort changes during the daily life of individuals with and without vocal hyperfunction.

Changes in the Daily Phonotrauma Index Following the Use of Voice Therapy as the Sole Treatment for Phonotraumatic Vocal Hyperfunction in Females.

Purpose The aim of this study was to use the Daily Phonotrauma Index (DPI) to quantify group-based changes in the daily voice use of patients with phonotraumatic vocal hyperfunction (PVH) after receiving voice therapy as the sole treatment. This is part of an ongoing effort to validate an updated theoretical framework for PVH. Method A custom-designed ambulatory voice monitor was used to collect 1 week of pre- and posttreatment data from 52 female patients with PVH. Normative weeklong data were also obtained from 52 matched controls. Each week was represented by the DPI, which is a combination of neck-surface acceleration magnitude skewness and the standard deviation of the difference between the first and second harmonic magnitudes. Results Compared to pretreatment, the DPI statistically decreased towards normal in the patient group after treatment (Cohen's d = -0.25). The posttreatment patient group's DPI was still significantly higher than the control group (d = 0.68). Conclusions The DPI showed the pattern of improved ambulatory voice use in a group of patients with PVH following voice therapy that was predicted by the updated theoretical framework. Per the prediction, voice therapy was associated with a decreased potential for phonotrauma in daily voice use, but the posttreatment patient group data were still significantly different from the normative control group data. This posttreatment difference is interpreted as reflecting the impact on voice use of the persistence of phonotrauma-induced structural changes to the vocal folds. Further validation of the DPI is needed to better understand its potential clinical use.

Differences in Daily Voice Use Measures Between Female Patients With Nonphonotraumatic Vocal Hyperfunction and Matched Controls.

Purpose The purpose of this study was to obtain a more comprehensive understanding of the pathophysiology and impact on daily voice use of nonphonotraumatic vocal hyperfunction (NPVH). Method An ambulatory voice monitor collected 1 week of data from 36 patients with NPVH and 36 vocally healthy matched controls. A subset of 11 patients with NPVH were monitored after voice therapy. Daily voice use measures included neck-skin acceleration magnitude, fundamental frequency (f o), cepstral peak prominence (CPP), and the difference between the first and second harmonic magnitudes (H1-H2). Additional comparisons included 118 patients with phonotraumatic vocal hyperfunction (PVH) and 89 additional vocally healthy controls. Results The NPVH group, compared to the matched control group, exhibited increased f o (Cohen's d = 0.6), reduced CPP (d = -0.9), and less positive H1-H2 skewness (d = -1.1). Classifiers used CPP mean and H1-H2 mode to maximally differentiate the NPVH and matched control groups (area under the receiver operating characteristic curve of 0.78). Classifiers performed well on unseen data: the logit decreased in patients with NPVH after therapy; ≥ 85% of the control and PVH groups were identified as "normal" or "not NPVH," respectively. Conclusions The NPVH group's daily voice use is less periodic (CPP), is higher pitched (f o), and has less abrupt vocal fold closure (H1-H2 skew) compared to the matched control group. The combination of CPP mean and H1-H2 mode appears to reflect a pathophysiological continuum in NPVH patients of inefficient phonation with minimal potential for phonotrauma. Further validation of the classification model is needed to better understand potential clinical uses. Supplemental Material https://doi.org/10.23641/asha.14390771.

Differences Between Female Singers With Phonotrauma and Vocally Healthy Matched Controls in Singing and Speaking Voice Use During 1 Week of Ambulatory Monitoring.

Purpose Previous ambulatory voice monitoring studies have included many singers and have combined speech and singing in the analyses. This study applied a singing classifier to the ambulatory recordings of singers with phonotrauma and healthy controls to determine if analyzing speech and singing separately would reveal voice use differences that could provide new insights into the etiology and pathophysiology of phonotrauma in this at-risk population. Method Forty-two female singers with phonotrauma (vocal fold nodules or polyps) and 42 healthy matched controls were monitored using an ambulatory voice monitor. Weeklong statistics (average, standard deviation, skewness, kurtosis) for sound pressure level (SPL), fundamental frequency, cepstral peak prominence, the magnitude ratio of the first two harmonics (H1-H2 ), and three vocal dose measures were computed from the neck surface acceleration signal and separated into singing and speech using a singing classifier. Results Mixed analysis of variance models found expected differences between singing and speech in each voice parameter, except SPL kurtosis. SPL skewness, SPL kurtosis, and all H1-H2 distributional parameters differentiated patients and controls when singing and speech were combined. Interaction effects were found in H1-H2 kurtosis and all vocal dose measures. Patients had significantly higher vocal doses in speech compared to controls. Conclusions Consistent with prior work, the pathophysiology of phonotrauma in singers is characterized by more abrupt/complete glottal closure (decreased mean and variation for H1-H2 ) and increased laryngeal forces (negatively skewed SPL distribution) during phonation. Application of a singing classifier to weeklong data revealed that singers with phonotrauma spent more time speaking on a weekly basis, but not more time singing, compared to controls. Results are used as a basis for hypothesizing about the role of speaking voice in the etiology of phonotraumatic vocal hyperfunction in singers.

Changes in a Daily Phonotrauma Index After Laryngeal Surgery and Voice Therapy: Implications for the Role of Daily Voice Use in the Etiology and Pathophysiology of Phonotraumatic Vocal Hyperfunction.

Purpose This study attempts to gain insights into the role of daily voice use in the etiology and pathophysiology of phonotraumatic vocal hyperfunction (PVH) by applying a logistic regression-based daily phonotrauma index (DPI) to predict group-based improvements in patients with PVH after laryngeal surgery and/or postsurgical voice therapy. Method A custom-designed ambulatory voice monitor was used to collect 1 week of pre- and postsurgery data from 27 female patients with PVH; 13 of these patients were also monitored after postsurgical voice therapy. Normative weeklong data were obtained from 27 matched controls. Each week was represented by the DPI, standard deviation of the difference between the first and second harmonic amplitudes (H1-H2). Results Compared to pretreatment, the DPI significantly decreased in the patient group after surgery (Cohen's d effect size = -0.86) and voice therapy (d = -1.06). The patient group DPI only normalized after voice therapy. Conclusions The DPI produced the expected pattern of improved ambulatory voice use across laryngeal surgery and postsurgical voice therapy in a group of patients with PVH. The results were interpreted as providing new objective information about the role of daily voice use in the etiology and pathophysiology of PVH. The DPI is viewed as an estimate of potential vocal fold trauma that relies on combining the long-term distributional characteristics of two parameters representing the magnitude of phonatory forces (neck-surface acceleration magnitude) and vocal fold closure dynamics (H1-H2). Further validation of the DPI is needed to better understand its potential clinical use.

Ambulatory monitoring of Lombard-related vocal characteristics in vocally healthy female speakers.

Speakers typically modify their voice in the presence of increased background noise levels, exhibiting the classic Lombard effect. Lombard-related characteristics during everyday activities were recorded from 17 vocally healthy women who wore an acoustic noise dosimeter and ambulatory voice monitor. The linear relationship between vocal sound pressure level and environmental noise level exhibited an average slope of 0.54 dB/dB and value of 72.8 dB SPL at 50 dBA when correlation coefficients were greater than 0.4. These results, coupled with analyses of spectral and cepstral vocal function measures, provide normative ambulatory Lombard characteristics for comparison with patients with voice-use related disorders.

Differences in Weeklong Ambulatory Vocal Behavior Between Female Patients With Phonotraumatic Lesions and Matched Controls.

Purpose Previous work using ambulatory voice recordings has shown no differences in average vocal behavior between patients with phonotraumatic vocal hyperfunction and matched controls. This study used larger groups to replicate these results and expanded the analysis to include distributional characteristics of ambulatory voice use and measures indicative of glottal closure. Method Subjects included 180 adult women: 90 diagnosed with vocal fold nodules or polyps and 90 age-, sex-, and occupation-matched controls with no history of voice disorders. Weeklong summary statistics (average, variability, skewness, kurtosis) of voice use were computed from neck-surface acceleration recorded using an ambulatory voice monitor. Voice measures included estimates of sound pressure level (SPL), fundamental frequency (f o), cepstral peak prominence, and the difference between the first and second harmonic magnitudes (H1-H2). Results Statistical comparisons resulted in medium-large differences (Cohen's d ≥ 0.5) between groups for SPL skewness, f o variability, and H1-H2 variability. Two logistic regressions (theory-based and stepwise) found SPL skewness and H1-H2 variability to classify patients and controls based on their weekly voice data, with an area under the receiver operating characteristic curve of 0.85 and 0.82 on training and test sets, respectively. Conclusion Compared to controls, the weekly voice use of patients with phonotraumatic vocal hyperfunction reflected higher SPL tendencies (negatively skewed SPL) with more abrupt glottal closure (reduced H1-H2 variability, especially toward higher values). Further work could examine posttreatment data (e.g., after surgery and/or therapy) to determine the extent to which these differences are associated with the etiology and pathophysiology of phonotraumatic vocal fold lesions.

Impact of Nonmodal Phonation on Estimates of Subglottal Pressure From Neck-Surface Acceleration in Healthy Speakers.

Purpose The purpose of this study was to evaluate the effects of nonmodal phonation on estimates of subglottal pressure (Ps) derived from the magnitude of a neck-surface accelerometer (ACC) signal and to confirm previous findings regarding the impact of vowel contexts and pitch levels in a larger cohort of participants. Method Twenty-six vocally healthy participants (18 women, 8 men) were asked to produce a series of p-vowel syllables with descending loudness in 3 vowel contexts (/a/, /i/, and /u/), 3 pitch levels (comfortable, high, and low), and 4 elicited phonatory conditions (modal, breathy, strained, and rough). Estimates of Ps for each vowel segment were obtained by averaging the intraoral air pressure plateau before and after each segment. The root-mean-square magnitude of the neck-surface ACC signal was computed for each vowel segment. Three linear mixed-effects models were used to statistically assess the effects of vowel, pitch, and phonatory condition on the linear relationship (slope and intercept) between Ps and ACC signal magnitude. Results Results demonstrated statistically significant linear relationships between ACC signal magnitude and Ps within participants but with increased intercepts for the nonmodal phonatory conditions; slopes were affected to a lesser extent. Vowel and pitch contexts did not significantly affect the linear relationship between ACC signal magnitude and Ps. Conclusion The classic linear relationship between ACC signal magnitude and Ps is significantly affected when nonmodal phonation is produced by a speaker. Future work is warranted to further characterize nonmodal phonatory characteristics to improve the ACC-based prediction of Ps during naturalistic speech production.

Automatic speech and singing classification in ambulatory recordings for normal and disordered voices.

Ambulatory voice monitoring is a promising tool for investigating phonotraumatic vocal hyperfunction (PVH), associated with the development of vocal fold lesions. Since many patients with PVH are professional vocalists, a classifier was developed to better understand phonatory mechanisms during speech and singing. Twenty singers with PVH and 20 matched healthy controls were monitored with a neck-surface accelerometer-based ambulatory voice monitor. An expert-labeled ground truth data set was used to train a logistic regression on 15 subject-pairs with fundamental frequency and autocorrelation peak amplitude as input features. Overall classification accuracy of 94.2% was achieved on the held-out test set.

Intervention Outcomes of Two Treatments for Muscle Tension Dysphonia: A Randomized Controlled Trial.

Purpose The aim of this study was to test the hypothesis that stretch-and-flow voice therapy (SnF) is noninferior to resonant voice therapy (RVT) for speakers with muscle tension dysphonia. Method Participants with primary muscle tension dysphonia were randomly assigned to 1 of 2 treatment groups. Participants received 6 sessions of either SnF or RVT for 6 weeks (1 session per week). Pretreatment and posttreatment audio recordings of sustained vowels and connected speech were acquired. Response to treatment was assessed using the voice handicap index (VHI) as the primary outcome measure. Secondary outcome measures included the acoustic voice quality index, the smoothed cepstral peak prominence, and scales from the Consensus Auditory-Perceptual Evaluation of Voice instrument. Data were analyzed for 21 participants who completed the study (12 in the SnF group, 9 in the RVT group). Results Direction of change for the primary outcome measure and all 3 secondary outcome measures at posttreatment was in the direction of improvement for both SnF and RVT. Confidence intervals for VHI measures did not cross the null effect line on forest plots, suggesting significant effects for both treatments on the primary outcome measure. The effect sizes for pretreatment to posttreatment changes in VHI were large for both treatment groups. Similar results were found for the secondary acoustic outcome measures. There were statistically significant pretreatment to posttreatment changes in the primary and secondary outcome measures for patients receiving both treatments, indicating significant improvement in response to both RVT and SnF. There were no statistically significant differences in pretreatment to posttreatment changes in the primary outcome measure or any secondary outcome measure between the two groups. The within-group pretreatment to posttreatment changes in Consensus Auditory-Perceptual Evaluation of Voice scales did not reach statistical significance for either RVT or SnF. Conclusions Both SnF and RVT produced positive treatment response in speakers with muscle tension dysphonia, with no statistically significant difference in the outcome measures between the two treatments. This suggests that SnF is noninferior to RVT and that both are effective options for treating vocal hyperfunction. Results from this study also support previous findings documenting the sensitivity of multidimensional acoustic measurements to treatment response.

Correlating an Ambulatory Voice Measure to Electrodermal Activity in Patients with Vocal Hyperfunction.

We investigate the connection between the autonomic nervous system and the voice in patients with vocal hyperfunction and healthy-control groups. We present a methodology and preliminary results of two multi-modal measurement streams that capture this relationship. Subjects were instrumented for daily, ambulatory collection of their voice and wrist-based electrodermal activity. Measures of vocal function (e.g., fundamental frequency) were computed, as well as measures of autonomic function (e.g., skin conductance response). Spearman correlation coefficients were calculated to measure the relationship between vocal and autonomic function over sliding windows throughout each observation day. We found preliminary evidence that patients with a subtype of vocal hyperfunction (non-phonotraumatic vocal hyperfunction) exhibit a coupling between the autonomic nervous system and the vocal system. Understanding how the autonomic nervous system interacts with the voice may provide new insights into the etiology/pathophysiology of vocal hyperfunction and improve prevention, diagnosis and treatment of these disorders.