Reliability of clinical office-based laryngeal electromyography in vocally healthy adults.

OBJECTIVE: This study aimed to conduct a 3-session reliability assessment of the laryngeal electromyography (LEMG) signal in healthy participants during intensity controlled vocalization tasks. We hypothesized that vocal intensity level and testing session would affect LEMG measures. METHODS: This prospective study used a 2-factor repeated measures design. Seven participants underwent bipolar needle LEMG of the right thyroarytenoid muscle. Data were collected over 3 testing sessions using vocalization tasks performed with visually guided intensity feedback targets (65 and 75 dB SPL). Root mean square amplitudes in microvolts were analyzed for within-session and between-session reliability. RESULTS: The main effect for intensity was found to approach significance (F = 5.71, P = .054). However, intraclass correlation coefficients (ICCs) using a 2-factor mixed random effect model indicated poor to fair signal reliability between testing sessions (ICC = 0.56 at 65 dB, 0.40 at 70 dB). Intraclass correlation coefficients for within-session data indicated excellent reliability for all testing conditions (0.84-0.98). CONCLUSION: Using a quantitative analysis protocol to inform an essentially qualitative technique, our results indicated that there was generally poor to fair reliability in the LEMG signal over testing sessions. Vocal intensity was an important variable that affected LEMG signal reliability. Standardization of LEMG protocols using vocal control parameters and quantitative analyses may help improve LEMG reliability in clinical settings.

Variability in Voice Characteristics of Female Speakers With Phonotraumatic Vocal Fold Lesions.

OBJECTIVE: To examine the variability of lesion characteristics and vocal function in female speakers with phonotraumatic vocal fold lesions (PVFLs). STUDY DESIGN: Prospective Cohort Study METHODS: Thirty adult female speakers with PVFL who were participating in voice therapy were recruited to complete a multidimensional voice analysis at four time points across 1 month. Analysis comprised self-ratings of effort and vocal function, expert ratings of videostroboscopy and audio recordings, and instrumental evaluation by selected aerodynamic and acoustic parameters. The degree of variability across time for each individual was assessed against a minimal clinically important difference threshold. RESULTS: A high degree of variability across time was observed for participant self-ratings of perceived effort and vocal function, and for instrumental parameters. The greatest degree of variability was observed in aerodynamic measures of airflow and pressure, and the acoustic parameter semitone range. Comparatively less variability was observed in perceptual evaluation of speech, and lesion characteristics via stroboscopy still images. Findings suggest that individuals with all PVFL types and sizes present with variability in function across time, with the greatest degree of variability in function observed in participants with large lesions and vocal fold polyps. CONCLUSION: Variability is observed in voice characteristics of female speakers with PVFLs across 1 month despite general stability in lesion presentation, suggesting vocal function can change despite the presence of laryngeal pathology. This study highlights the need to explore individual functional and lesion responses across time to determine potential for change and improvement in both aspects when selecting treatment options.

The Immediate Impact of Targeted Exercises on Voice Characteristics in Female Speakers With Phonotraumatic Vocal Fold Lesions.

OBJECTIVE: To examine the immediate impact of 30 minutes of targeted voice exercises on measures of vocal function and lesion characteristics in female speakers with phonotraumatic vocal fold lesions (PVFLs). STUDY DESIGN: Prospective cohort study. METHOD: Twenty-nine (n = 29) female subjects with PVFLs completed a 30 minutes targeted voice exercise protocol and a multidimensional voice analysis was conducted immediately pre and post-exercise. Analysis included expert perceptual evaluation of connected speech and stroboscopy recordings, instrumental analysis by selected aerodynamic and acoustic parameters, and self-ratings of effort and vocal function by participants. The direction and magnitude of the change from pre- to post-exercise for each individual across parameters was assessed against a Minimal Clinically Important Difference criteria. RESULTS: Variability was observed among participants in their response to exercise and across parameters. Multidirectional change in function was demonstrated across instrumental parameters, with observations of both improvement and decline. The most consistent change observed was a reduced PTP post-exercises for 38% of participants (n = 11), and the greatest magnitude of change was observed in aerodynamic measures of airflow and pressure, and the acoustic parameter semitone range. Variability in the direction of change across instrumental measures was observed for 24% of participants (n = 7), while consistent improved function was seen for 45% (n = 13), declined function for 17% (n = 5) and no change for 14% (n = 4). Participant's self-reported effort and function post-exercise was also multidirectional, with the greatest number reporting improvement. Comparatively little change was observed in perceptual evaluation of speech and stroboscopy recordings. Findings suggest that individuals with all lesion types, sizes and liabilities have the potential to improve vocal function immediately post-exercises according to instrumental measures, with the greatest magnitude of change observed in participants with large lesions. Although participants' characteristics did not differentiate, those with nodules or polyps tended to report improvement in function and reduced effort post-exercise, whereas those with a diagnosis of pseudocyst/s or a unilateral lesion appeared to report no change or declined function. CONCLUSION: Change in measures of vocal function was observed in female speakers with PVFLs immediately following a 30 minutes targeted exercises protocol. Many demonstrated improvement but a high degree of variability was observed in the way speakers respond, and it is likely an individual's response is influenced by a range of factors. Self-rating scales, along with key instrumental parameters sensitive to the presence of PVFLs, may prove most useful in tracking initial change in the immediate and short-term duration in this population, and in assessing stimulability and candidacy for therapy. Further exploration is warranted of stimulability for immediate and cumulative change to achieve sustained improvement in function and efficiency across time.

The Impact of a Vocal Loading Task on Voice Characteristics of Female Speakers With Benign Vocal Fold Lesions.

OBJECTIVES: To examine the effect of a vocal loading task on measures of vocal structure and function in females with benign vocal fold lesions (BVFLs) and determine if change is observed in voice and lesion characteristics. STUDY DESIGN: Prospective cohort study. METHODS: Twenty-eight (n = 28) female subjects with phonotraumatic BVFLs completed a vocal loading task of 30 minutes of reading aloud at 75-85 dBA. Multidimensional voice evaluation was completed pre- and post-load, including audio and videostroboscopy recordings and images for expert perceptual ratings and acoustic and aerodynamic evaluation. Subjects also scored themselves using a 10 cm visual analogue scale for Perceived Phonatory Effort, and completed the Evaluation of Ability to Voice Easily, a 12 item self-report scale of current perceived speaking voice function. An exploratory rather than confirmatory approach to data analysis was adopted. The direction and magnitude of the change scores (pre- to post-load) for each individual, across a wide variety of instrumental and self-report measures, were assessed against a Minimal Clinically Important Difference criteria. RESULTS: Observations of change and the direction of change in vocal response of individuals with BVFLs to 30 minutes of loud vocal load was variable. Minimal to no change was noted for participants pre- to post-load as rated perceptually, for auditory and videostroboscopy samples. For most instrumental measures, change was shown for many participants including an overall improvement in aerodynamic and acoustic measures of function and efficiency post-load for 20 participants (77%) and decline in function for 4 participants (15%). Self-reported effort and vocal function post-load was multidirectional with similar numbers of participants reporting no change, improved function or a decline. CONCLUSION: Subjects with BVFLs demonstrate change in vocal function following 30 minutes of vocal load. While this change can be variable and multidirectional, overall improvement was observed in instrumental measures of function and efficiency for most participants. Some participants perceived this change to be an increase in effort, some a reduction in effort and some perceived no change. Improved vocal function despite relative lesion stability can seemingly occur after loading in some pathological voices.

Limbic and cortical control of phonation for speech in response to a public speech preparation stressor.

Knowledge on brain networks subserving vocalization in vocally healthy individuals under various task conditions is scarce but paramount to understand voice disorders. The aims of our study were to determine (1) the effect of social-evaluative stress on the central neural control of phonation underlying speech production; and (2) the neural signature, personality profile, and aerodynamic vocal function in relation to salivary cortisol responses. Thirteen vocally healthy females underwent an event-related sparse-sampling fMRI protocol consisting of voiced and whispered sentence productions with and without exposure to the social-evaluative stressor public speaking anticipation. Participants completed a personality questionnaire, rating scales of negative emotional state, and provided salivary cortisol samples. In the total sample, the task contrast of voiced productions revealed that stressor exposure resulted in a peak activation in the right caudate with concomitant deactivations in the bilateral pgACC and aMCC, and right IFG, BA 9, BA 10, insula, putamen, and thalamus. There were individual differences in stressor-induced brain activations as a function of stress reactivity with greater cortisol reactivity linked with lower laryngeal motor cortex activity and lower scores on aspects of extraversion. Our data confirm that stress alters the phonatory control for speech production through limbic-motor interactions. The findings support the Trait Theory of Voice Disorders (Roy and Bless 2000) and help provide critical insights to the study of voice disorders such as primary muscle tension dysphonia.

Establishing a new animal model for the study of laryngeal biology and disease: an anatomic study of the mouse larynx.

PURPOSE: Animal models have contributed greatly to the study of voice, permitting the examination of laryngeal biology and the testing of surgical, medical, and behavioral interventions. Various models have been used. However, until recently, the mouse (Mus musculus) has not been used in laryngeal research, and features of the mouse larynx have not been defined. Therefore, the purpose of this study was to qualitatively describe mouse laryngeal anatomy in relation to known human anatomy. METHODS: Larynges of 7 C57BL mice were examined and photographed under stereotactic and light microscopy. RESULTS: The authors found that mouse laryngeal organization was similar to that of humans. The hyoid bone and epiglottal, thyroid, cricoid, and arytenoid cartilages were identified. An additional cartilage was present ventrally. Thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, and cricothyroid muscles were grossly positioned as in humans. Interarytenoid muscles were not present; however, a functional counterpart was identified. CONCLUSIONS: The authors provide an initial description of mouse laryngeal anatomy. Because of its amenability to genetic engineering, the mouse is the premiere model for the study of disease and the testing of interventions. Introduction of the mouse model for laryngeal study offers a tool for the study of normal laryngeal cell biology and tissue response to disease processes.

Descriptive Analysis of the Interactive Patterning of the Vocalization Subsystems in Healthy Participants: A Dynamic Systems Perspective.

Purpose Normative data for many objective voice measures are routinely used in clinical voice assessment; however, normative data reflect vocal output, but not vocalization process. The underlying physiologic processes of healthy phonation have been shown to be nonlinear and thus are likely different across individuals. Dynamic systems theory postulates that performance behaviors emerge from the nonlinear interplay of multiple physiologic components and that certain patterns are preferred and loosely governed by the interactions of physiology, task, and environment. The purpose of this study was to descriptively characterize the interactive nature of the vocalization subsystem triad in subjects with healthy voices and to determine if differing subgroups could be delineated to better understand how healthy voicing is physiologically generated. Method Respiratory kinematic, aerodynamic, and acoustic formant data were obtained from 29 individuals with healthy voices (21 female and eight male). Multivariate analyses were used to descriptively characterize the interactions among the subsystems that contributed to healthy voicing. Results Group data revealed representative measures of the 3 subsystems to be generally within the boundaries of established normative data. Despite this, 3 distinct clusters were delineated that represented 3 subgroups of individuals with differing subsystem patterning. Seven of the 9 measured variables in this study were found to be significantly different across at least 1 of the 3 subgroups indicating differing physiologic processes across individuals. Conclusion Vocal output in healthy individuals appears to be generated by distinct and preferred physiologic processes that were represented by 3 subgroups indicating that the process of vocalization is different among individuals, but not entirely idiosyncratic. Possibilities for these differences are explored using the framework of dynamic systems theory and the dynamics of emergent behaviors. A revised physiologic model of phonation that accounts for differences within and among the vocalization subsystems is described. Supplemental Material https://doi.org/10.23641/asha.7616462.

Vocal function exercises for normal voice: With and without semi-occlusion.

PURPOSE: This study examined the effect of varying degrees of vocal tract (VT) occlusion used during Vocal Function Exercises (VFEs) on attainment of maximum phonation time (MPT) goals in normal voice. Greater VT occlusion was expected to result in increased MPT. The overarching goal was to determine whether the semi-occluded vocal tract (SOVT) posture used during VFEs could be modified while preserving efficacy. METHOD: Twenty-six females ages 18-30 participated in this pre-post longitudinal group study. Participants were randomly assigned to three experimental groups and completed a six-week VFE protocol. The first group performed exercises using the prescribed SOVT posture; the second group used the vowel /o/; group three used the vowel /a/. The primary outcome measure was MPT as performed on the exercise tasks using the assigned vocal tract posture. RESULT: MPT significantly improved in the prescribed SOVT group, but did not significantly improve in the modified /o/ and /a/ groups. CONCLUSION: The SOVT posture used during VFEs is modifiable to a small extent without significantly undermining efficacy. Changes in MPT are less robust with reduced VT occlusion. Research in a clinical population is warranted.

Aging Voice Index (AVI): Reliability and Validity of a Voice Quality of Life Scale for Older Adults.

Changes in voice in aging adults impact their ability to use their voice to communicate in all situations and can lead to decreased quality of life (QOL). The primary objective of this study was to determine the validity and reliability of the Aging Voice Index (AVI)-a tool specifically designed for aging adults with voice disorders. A total of 92 older adults were asked to complete the Voice-Related Quality of Life Scale (VRQOL) and the AVI as well as provide their self-perceived voice severity rating of their voice problem and demographic information. Intraclass correlation for test-retest reliability was 0.952. The AVI was highly correlated to the VRQOL (P < 0.0001). Additionally, the AVI score was found to distinguish between self-rated voice quality (P < 0.0001) and diagnostic voice categories (P < 0.0001). No significant differences were identified for sex or race. The AVI is a valid and reliable quality of life assessment for older adults with voice disorders. The AVI will capture the quality of life impact a voice disorder has on older adults. Future studies will further explore differences in clinical diagnoses and identify clinically significant changes in pre-to post-AVI scores.

Laryngeal muscles are spared in the dystrophin deficient mdx mouse.

PURPOSE: Duchenne muscular dystrophy (DMD) is caused by the loss of the cytoskeletal protein, dystrophin. The disease leads to severe and progressive skeletal muscle wasting. Interestingly, the disease spares some muscles. The purpose of the study was to determine the effects of dystrophin deficiency on 2 intrinsic laryngeal muscles, the posterior cricoarytenoid and the thyroarytenoid, in the mouse model. METHOD: Larynges from dystrophin-deficient mdx and normal mice were examined histologically. RESULTS: Results demonstrate that despite the absence of dystrophin in the mdx laryngeal muscles, membrane damage, inflammation, necrosis, and regeneration were not detected in the assays performed. CONCLUSIONS: The authors concluded that these muscles are 1 of only a few muscle groups spared in this model of dystrophin deficiency. The muscles may count on intrinsic and adaptive protective mechanisms to cope with the absence of dystrophin. Identifying these protective mechanisms may improve DMD management. The study also highlights the unique aspects of the selected laryngeal skeletal muscles and their dissimilarity to limb skeletal muscle.

Videophone-delivered voice therapy: a comparative analysis of outcomes to traditional delivery for adults with Parkinson's disease.

Individuals with idiopathic Parkinson's disease (IPD) usually develop a speech disorder characterized by reduced loudness, hoarse and breathy voice, monotony of pitch, short rushes of speech, and imprecise consonants. The inability to effectively communicate impairs their ability to function in society and quality of life. A successful program developed to improve speech in these individuals is the Lee Silverman Voice Treatment (LSVT). A critical component of this treatment is intense daily therapy for 4 weeks, a regimen that is difficult for many elderly patients to complete. Treatment delivered through videophones placed in the homes of individuals with IPD offers an alternative and could improve accessibility of treatment if the results were the same. This study compared the outcomes of LSVT delivered via videophones to the outcomes of traditional treatment delivered face-to-face.

Aging thyroarytenoid and limb skeletal muscle: lessons in contrast.

Voice production is vital throughout life because it allows for the communication of basic needs as well as the pursuit and enjoyment of social encounters. Unfortunately, for many older individuals the ability to produce voice is altered. Structural and functional declines in the neuromuscular system occur with aging and likely contribute to the modification of voice. One specific target of the aging process is the thyroarytenoid (TA) muscle, the primary muscle of voice production. The objectives of this overview article are to (1) share current findings related to the aging of limb skeletal muscle, (2) identify age-related morphological and physiological features of TA muscle, (3) compare and contrast age-related changes in TA with those in limb skeletal muscle, and (4) describe therapies for reversing sarcopenia in limb muscle and consider the applicability of these therapies for addressing vocal fold atrophy and age-related voice changes. The article shares current knowledge from the basic sciences related to skeletal muscle aging and compares/contrasts typical muscle aging to TA aging. Current evidence suggests that (1) the TA muscle undergoes notable remodeling with age, (2) aging of the TA is multifactorial, resulting from a myriad of neurologic, metabolic, and hormonal changes, many of which are distinct from the age-related processes of typical limb skeletal muscle, (3) investigation of the aging of the TA and its role in the aging of voice is in its infancy, and (4) potential behavioral and nonbehavioral therapies for reversing aging of the TA must be further examined.

Vocalization Subsystem Responses to a Temporarily Induced Unilateral Vocal Fold Paralysis.

Purpose: The purpose of this study is to quantify the interactions of the 3 vocalization subsystems of respiration, phonation, and resonance before, during, and after a perturbation to the larynx (temporarily induced unilateral vocal fold paralysis) in 10 vocally healthy participants. Using dynamic systems theory as a guide, we hypothesized that data groupings would emerge revealing context-dependent patterns in the relationships of variables representing the 3 vocalization subsystems. We also hypothesized that group data would mask important individual variability important to understanding the relationships among the vocalization subsystems. Method: A perturbation paradigm was used to obtain respiratory kinematic, aerodynamic, and acoustic formant measures from 10 healthy participants (8 women, 2 men) with normal voices. Group and individual data were analyzed to provide a multilevel analysis of the data. A 3-dimensional state space model was constructed to demonstrate the interactive relationships among the 3 subsystems before, during, and after perturbation. Results: During perturbation, group data revealed that lung volume initiations and terminations were lower, with longer respiratory excursions; airflow rates increased while subglottic pressures were maintained. Acoustic formant measures indicated that the spacing between the upper formants decreased (F3-F5), whereas the spacing between F1 and F2 increased. State space modeling revealed the changing directionality and interactions among the 3 subsystems. Conclusions: Group data alone masked important variability necessary to understand the unique relationships among the 3 subsystems. Multilevel analysis permitted a richer understanding of the individual differences in phonatory regulation and permitted subgroup analysis. Dynamic systems theory may be a useful heuristic to model the interactive relationships among vocalization subsystems. Supplemental Material: https://doi.org/10.23641/asha.5913532.

Reflux symptom index versus reflux finding score.

OBJECTIVES: We examined the correlation between the Reflux Symptom Index (RSI) and the Reflux Finding Score (RFS) to determine the laryngeal signs and symptoms that were most significantly correlated. METHODS: Forty randomly selected patients were included in the study. A retrospective chart review was performed for patients who fit the inclusion criteria. Videostroboscopic samples for the study group were reviewed and RFS-rated by 6 experienced raters on 2 different occasions to evaluate the interrater and intrarater reliability. The RSI and the RFS were statistically compared regarding both the total scores and the individual parameters. RESULTS: The RFS ranged from 0 to 20, and the RSI varied from 14 to 38. There was a high agreement between the raters' scores, demonstrating high interrater and intrarater reliability for RFS. Additionally, the RSI and RFS were highly correlated (p < .0001). Hoarseness was highly correlated with vocal fold edema and thick laryngeal mucus (p < .01), and excessive throat clearing correlated significantly with thick endolaryngeal mucus (p < .01). CONCLUSIONS: The study demonstrates a highly significant correlation between the RFS and the RSI.

Reliability of speech-language pathologist and otolaryngologist ratings of laryngeal signs of reflux in an asymptomatic population using the reflux finding score.

OBJECTIVE: To determine inter- and intrajudge agreement in rating signs of laryngopharyngeal reflux (LPR) under "ideal" conditions: Experienced coworkers in a practice devoted to voice-disordered patients, raters trained in the items on a standardized scale, raters from both speech-language pathology (SLP) and otolaryngology, and raters of asymptomatic participants. STUDY DESIGN: Prospective study using a scale to rate videolaryngoscopic examinations. METHODS: Two SLPs and two otolaryngologists used the Reflux Finding Scale (RFS) to independently rate videotapes of endoscopic examinations for 30 participants asymptomatic of reflux. RESULTS: Thirteen (43%) were assigned a total score >7, indicative of LPR, by at least one rater. Intraclass correlation coefficients showed a significant lack of agreement in total scores provided by the otolaryngologists and by all raters combined. One otolaryngologist and the two SLPs demonstrated good interrater agreement in total scores. McNamar's statistic and Poisson regression modeling showed differences in rater agreement for many individual items. Repeated ratings of four participants showed no significant differences, indicating good intrarater reliability. CONCLUSIONS: Level of rater agreement regarding the presence and the severity of physical findings attributed to LPR within and between otolaryngologists and SLPs differed. Given the role each profession plays in the diagnosis and treatment of LPR and related voice disturbances, higher levels of interprofessional agreement are desired. Results support the need for greater consensus among professionals regarding the discreet features of physical findings associated with LPR, a fuller understanding of normal variants, and greater emphasis on interrater reliability when rating physical findings.

Immediate Effects of the Vocal Function Exercises Semi-Occluded Mouth Posture on Glottal Airflow Parameters: A Preliminary Study.

OBJECTIVES: The study aimed to quantify immediate alterations in the airflow glottogram between the Vocal Function Exercises semi-occluded mouth posture (/ol/ with lip buzz) and the sustained vowel /o/ in individuals with normal voices, and to determine if noted changes were in agreement with established semi-occluded vocal tract aerodynamic theory. Based on semi-occluded vocal tract aerodynamic theory, we hypothesized the following immediate changes in the flow glottogram during the /ol-buzz/ condition: a greater open quotient, a greater skewing quotient, a greater maximum flow declination rate, increased average airflow, decreased peak airflow, and increased minimum airflow. METHODS: A cohort of eight men with normal voices produced the sustained vowel /o/ and the Vocal Function Exercises semi-occluded mouth posture (/ol-buzz/). Flow glottograms for both conditions were obtained from the inverse-filtered oral airflow signal via a circumferentially vented pneumotachograph mask. RESULTS: Data revealed that open quotient and minimum airflow rates increased significantly between conditions. All other measures trended in the directions predicted by aerodynamic theory, but were not statistically significant. CONCLUSIONS: The Vocal Function Exercises semi-occluded mouth posture appeared to provide an effective vocal tract semi-occlusion that immediately altered the flow glottogram in accordance with predictions made by computer-modeled aerodynamic theory.

Subcutaneous Neurotrophin 4 Infusion Using Osmotic Pumps or Direct Muscular Injection Enhances Aging Rat Laryngeal Muscles.

Laryngeal dysfunction in the elderly is a major cause of disability, from voice disorders to dysphagia and loss of airway protective reflexes. Few, if any, therapies exist that target age-related laryngeal muscle dysfunction. Neurotrophins are involved in muscle innervation and differentiation of neuromuscular junctions (NMJs). It is thought that neurotrophins enhance neuromuscular transmission by increasing neurotransmitter release. The neuromuscular junctions (NMJs) become smaller and less abundant in aging rat laryngeal muscles, with evidence of functional denervation. We explored the effects of NTF4 for future clinical use as a therapeutic to improve function in aging human laryngeal muscles. Here, we provide the detailed protocol for systemic application and direct injection of NTF4 to investigate the ability of aging rat laryngeal muscle to remodel in response to NTF4 application. In this method, rats either received NTF4 either systemically via osmotic pump or by direct injection through the vocal folds. Laryngeal muscles were then dissected and used for histological examination of morphology and age-related denervation.

Enhancement of aging rat laryngeal muscles with endogenous growth factor treatment.

Clinical evidence suggests that laryngeal muscle dysfunction is associated with human aging. Studies in animal models have reported morphological changes consistent with denervation in laryngeal muscles with age. Life-long laryngeal muscle activity relies on cytoskeletal integrity and nerve-muscle communication at the neuromuscular junction (NMJ). It is thought that neurotrophins enhance neuromuscular transmission by increasing neurotransmitter release. We hypothesized that treatment with neurotrophin 4 (NTF4) would modify the morphology and functional innervation of aging rat laryngeal muscles. Fifty-six Fischer 344xBrown Norway rats (6- and 30-mo age groups) were used to evaluate to determine if NTF4, given systemically (n = 32) or directly (n = 24), would improve the morphology and functional innervation of aging rat thyroarytenoid muscles. Results demonstrate the ability of rat laryngeal muscles to remodel in response to neurotrophin application. Changes were demonstrated in fiber size, glycolytic capacity, mitochondrial, tyrosine kinase receptors (Trk), NMJ content, and denervation in aging rat thyroarytenoid muscles. This study suggests that growth factors may have therapeutic potential to ameliorate aging-related laryngeal muscle dysfunction.

Three treatments for teachers with voice disorders: a randomized clinical trial.

Voice problems are a common occupational hazard of teaching school, yet few studies exist that have objectively evaluated treatment approaches aimed at rehabilitating these occupation-related voice disorders. This randomized clinical trial used patient-based treatment outcome measures to evaluate the effectiveness of three treatment programs. Sixty-four teachers with voice disorders were randomly assigned to 1 of 3 treatment groups: voice amplification using the ChatterVox portable amplifier (VA; n = 25), resonance therapy (RT; n = 19), and respiratory muscle training (RMT; n = 20). Before and after a 6-week treatment phase, all teachers completed (a) the Voice Handicap Index (VHI; B. H. Jacobson et al., 1997), an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders, and (b) a voice severity self-rating scale. Both intention-to-treat and as-treated analyses revealed that only the VA and RT groups reported significant reductions in mean VHI scores and in voice severity self-ratings following treatment. Furthermore, results from a posttreatment questionnaire regarding the perceived benefits of treatment showed that compared to RT and RMT, teachers in the VA group reported significantly more overall voice improvement, greater vocal clarity, and greater ease of speaking and singing voice following treatment. These findings replicate previous results from an earlier clinical trial confirming the efficacy of VA and provide new evidence to support RT as an effective treatment alternative for voice problems in teachers. The results are discussed in the context of uneven levels of self-reported compliance and disparate dropout rates among the treatment groups.

Voice amplification versus vocal hygiene instruction for teachers with voice disorders: a treatment outcomes study.

Voice problems are common among schoolteachers. This prospective, randomized clinical trial used patient-based treatment outcomes measures combined with acoustic analysis to evaluate the effectiveness of two treatment programs. Forty-four voice-disordered teachers were randomly assigned to one of three groups: voice amplification using the ChatterVox portable amplifier (VA, n = 15), vocal hygiene (VH, n = 15), and a nontreatment control group (n = 14). Before and after a 6-week treatment phase, all teachers completed: (a) the Voice Handicap Index (VHI), an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders; (b) a voice severity self-rating scale; and (c) an audiorecording for later acoustic analysis. Based on pre- and posttreatment comparisons, only the amplification group experienced significant reductions on mean VHI scores (p = .045), voice severity self-ratings (p = .012), and the acoustic measures of percent jitter (p = .031) and shimmer (p = .008). The nontreatment control group reported a significant increase in level of vocal handicap as assessed by the VHI (p = .012). Although most pre- to posttreatment changes were in the desired direction, no significant improvements were observed within the VH group on any of the dependent measures. Between-group comparisons involving the three possible pairings of the groups revealed a pattern of results to suggest that: (a) compared to the control group, both treatment groups (i.e., VA and VH) experienced significantly more improvement on specific outcomes measures and (b) there were no significant differences between the VA and VH groups to indicate superiority of one treatment over another. Results, however, from a posttreatment questionnaire regarding the perceived benefits of treatment revealed that, compared to the VH group, the VA group reported more clarity of their speaking and singing voice (p = .061), greater ease of voice production (p = .001), and greater compliance with the treatment program (p = .045). These findings clearly support the clinical utility of voice amplification as an alternative for the treatment of voice problems in teachers.