Effectiveness of voice therapy in patients with vocal fold nodules: a systematic search and narrative review

Systematic Review of Recurrence Rates of Benign Vocal Fold Lesions Following Surgery

OBJECTIVES

Benign vocal fold lesions which include vocal fold nodules, polyps, cysts and other lesions often recur after surgery and require additional treatments. This systematic review of the current literature evaluated the effects of adjunctive therapies in addition to surgical resection on the recurrence rates of benign vocal fold lesions in adults.

STUDY DESIGN

Systematic review.

METHODS

A search using relevant keywords in electronic databases was conducted. Extracted data include author, year of publication, patient demographics, diagnostic approach, lesion type, surgical procedure, type of adjunctive therapy and the rates of recurrence. Descriptive statistics were performed on the collected data when appropriate.

RESULTS

Eleven articles were identified with a total of 1085 patients. The total 1101 lesions studied included 591 (53.7%) polyps, 125 (11.4%) nodules, 146 (13.3%) cysts, 184 (16.7%) pseudocysts, 19 (1.7%) midfold masses, 18 (1.6%) sulcus vocalis and 18 (1.6%) varices. Besides surgery, adjunctive therapies included voice therapy, steroid injection and reflux medication. There were 141 reported lesion recurrences, with an average recurrence rate of 13.0%. The recurrence rate in studies with adjunctive therapies was 7.14%, and in studies with no adjunctive therapies it was 24.44%.

CONCLUSIONS

Available evidence suggests that adjunctive therapies following surgery are associated with decreased lesion recurrence rates. However, due to differences in sample size, inconsistent reporting of lesion characteristics, heterogeneity of adjunctive therapies, variability in follow-up time across studies, and other factors, it is not possible to determine exactly which adjunctive therapies are of significant benefit and which lesion types may benefit the most.

Short-Term Effects of Semi-Occluded Vocal Tract Therapy on the Phonation of Children With Vocal Fold Nodules: A Randomized Controlled Trial

PURPOSE

The aim was to determine and compare the short-term effects of two intensive semi-occluded vocal tract (SOVT) programs, "straw phonation" (SP) and "resonant voice therapy" (RVT), on the phonation of children with vocal fold nodules.

METHOD

A pretest-posttest randomized controlled study design was used. Thirty children aged 6-12 years were randomly assigned to the SP group (n = 11), RVT group (n = 11), or control group receiving indirect treatment (n = 8) for their voice problems. All participants received 11 hr of group voice therapy over four consecutive days. A multidimensional voice assessment consisting of both objective (dysphonia severity index and acoustic voice quality index) and subjective (pediatric voice handicap index and perceptual rating of overall severity) measures was performed pre- and posttherapy. Voice therapy effectiveness was evaluated using group-level analyses (linear mixed models) and individual-level analyses to investigate what proportion of participants changed to a clinically relevant degree.

RESULTS

Group-level analyses found no significant Time × Group interactions, indicating that the evolution over time did not differ among the three groups. Within-group effects of time showed a significant and equal improvement in dysphonia severity index in the SP and RVT groups and a significant improvement in perceptual rating of overall severity in the SP group. For dysphonia severity index, individual-level analyses showed that 36% and 45% of participants improved to a clinically relevant degree in the SP and RVT groups, respectively. For acoustic voice quality index, 38% improved to a clinically relevant degree in the SP group.

CONCLUSIONS

Results suggest that short-term intensive SOVT programs may have a positive effect on voice quality and vocal capacities of children with vocal fold nodules. Participants seem to benefit more from a SP program than a RVT program.

Biophysical aspects of mechanotransduction in cells and their physiological/biological implications in vocal fold vibration: a narrative review

Mechanotransduction is a crucial property in all organisms, modulating cellular behaviors in response to external mechanical stimuli. Given the high mobility of vocal folds, it is hypothesized that mechanotransduction significantly contributes to their tissue homeostasis. Recent studies have identified mechanosensitive proteins in vocal fold epithelia, supporting this hypothesis. Voice therapy, which, involves the mobilization of vocal folds, aims to rehabilitate vocal function and restore homeostasis. However, establishing a direct causal link between specific mechanical stimuli and therapeutic benefits is challenging due to the variability in voice therapy techniques. This challenge is further compounded when investigating biological benefits in humans. Vocal fold tissue cannot be biopsied without significant impairment of the vibratory characteristics of the vocal folds. Conversely, studies using vocal fold mimetic bioreactors have demonstrated that mechanical stimulation of vocal fold fibroblasts can lead to highly heterogeneous responses, depending on the nature and parameters of the induced vibration. These responses can either aid or impede vocal fold vibration at the physiological level. Future research is needed to determine the specific mechanical parameters that are biologically beneficial for vocal fold function.

Acoustic Measurements Through the Life Span: Jitter, Shimmer, and Standard Deviation of Fundamental Frequency

OBJECTIVE

To verify changes in acoustic parameters, namely jitter, shimmer, and standard deviation of the fundamental frequency (dp fo), through the life span of vocally healthy Brazilian Portuguese speakers.

METHOD

In total, 526 voice recordings of subjects without complaints and without vocal disorders, aged between 5 and 93 years old, were included. The recordings were divided into 12 age groups (5 to 7, 8 to 9, 10 to 11, 12, 13 to 15, 16 to 18, 19 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69, and 70 to 93 years old). Acoustic analysis was carried out, based on the sustained emission of the vowel /a/, extracting the parameters jitter, shimmer, and dp fo, using the Multi-Dimensional Voice Program software. The two-way ANOVAtest was used to investigate possible differences between age groups, followed by the Sidak Post-Hoc test.

RESULTS

Related to jitter, children present higher values compared with the elderly. In adults and the elderly, the jitter measurement does not reflect the changes resulting from aging in both sexes. Women have a higher jitter value compared with men. As for the shimmer, this measurement is high in the child population with stability during adulthood and, in the elderly, it was observed that the shimmer was sensitive to indicate vocal changes in the male population. In general, there are no sex differences on this measurement. Finally, for dp fo, the study found higher values in the child population, with a reduction with aging until stabilizing in adults and the elderly. Higher values were observed for females compared with males.

CONCLUSION

Jitter, shimmer, and dp fo changed through the life span, being elevated for the child population, remaining stable in the adult population, and with smaller changes during aging.

Pediatric Voice Handicap Index (pVHI): A Tool for Evaluating the Reliability and Validity of Voice Therapy in Children With Benign Vocal Fold Nodules

OBJECTIVES

benign vocal fold lesions (BVFLs) represent the most common etiology of voice disorders in paediatric population, cause of dysphonia by preventing full vocal fold closure and modifying vibratory characteristics. Of those pathologies, vocal fold nodules represent almost 63% of the cases in children between 0-14 years. Management may include a combination of phonosurgery, voice therapy and pharmacological treatment, but almost 95% of otolaryngologists recommend voice therapy as primary treatment. The Pediatric Voice Handicap Index (pVHI) is nowadays widely used and accepted in the evaluation and monitoring of paediatric patients with dysphonia. The aim of our study was to demonstrate the reliability and validity of PVHI in the evaluation of the effects of voice therapy as treatment of vocal fold nodules in the paediatric population.

PATIENTS AND METHOD

in this retrospective chart review twenty-seven (27) dysphonic patients with bilateral vocal fold nodules were treated with behavioral voice therapy approaches, and the PVHI surveys was administered to each patient parent's before and after therapy. The age of the patients ranged from 4 to 14 years (mean age 8.7 y-o); 17 (63%) were male and 10 (37%) females.

RESULTS

according to our results, behavioral voice therapy effectively improved pVHI scores from pre- to post-treatment in paediatric patients with bilateral vocal fold nodules.

Assessing the Effectiveness of Voice Therapy Techniques in Treating Dysphonia: An Otolaryngological Review

Dysphonia is a prevalent condition that can impact individuals across all age groups. It occurs when normal voice quality is altered, caused by structural and/or functional issues. Evaluation and assessment from clinicians are warranted if dysphonia persists for more than four weeks and/or is coupled with risk factors or other concerning clinical manifestations. Additionally, voice disorders can increase the risk of depression and anxiety disorders, as well as raise stress levels and lower self-reported health indicators. Dysphonia can have a substantial influence on interpersonal interactions and lower overall quality of life since effective communication relies significantly on spoken language. Hence, managing dysphonia is essential for enhancing communication abilities, improving quality of life, maintaining vocational functioning, promoting psychological well-being, and addressing underlying health concerns. Speech and language therapy, medical management, surgery, or a combination of the aforementioned are all possible treatments for dysphonia. Speech and language therapy is often the first-line treatment option for dysphonia patients who do not meet the criteria for surgical intervention. Voice therapy is often beneficial and remains the first line of treatment, even when patients approach with benign vocal fold nodules. A well-designed voice therapy program improves both the quality of life and vocal performance. The majority of the studies in the existing literature advocate for and report beneficial outcomes associated with voice therapy; however, more research is needed to provide evidence-based findings to guide clinical practice and achieve optimal outcomes. This comprehensive review elaborately highlights the utilization and efficacy of various voice therapeutic modalities utilized for the management of dysphonia in light of current literature.

Noninvasive Management of Voice Disorders: An Umbrella Review

OBJECTIVES

The aim of this study was to assess published systematic reviews that discussed noninvasive management of voice disorders. An umbrella review was conducted to collect, organize, and summarize narratively all available pharmacologic and voice therapy interventions.

STUDY DESIGN

Umbrella review of systematic reviews.

METHODS

Pertinent systematic reviews were identified by searching Pubmed/Medline and Embase. A primary screen identified studies related to voice. The second round of screening focused on studies that involved noninvasive management of voice disorders such as pharmacologic or voice therapy interventions. Variables of interest included study design, number of studies included in the review, target population, method of intervention, and outcomes.

RESULTS

Forty-three systematic reviews were eligible and included in the umbrella review. Ten studies focused on pharmacologic interventions, and 33 studies focused on voice therapy. Individual studies included in the systematic reviews ranged from 2-47, with a total of 601 studies overall.

CONCLUSIONS

This study provides a detailed review of all available systematic reviews on noninvasive management of voice disorders. Explored medications included proton pump inhibitors, calcium channel blockers, tricyclic antidepressants, antibiotics, corticosteroids, and hormone replacement. Explored voice therapy techniques included hydration, vocal function exercises, laryngeal manual therapy, respiratory exercise, biofeedback, phonation, coping strategies, and others. This may be utilized to guide therapeutic decision-making and identify current gaps in the literature that may warrant future investigation.

Current Practices in Voice Data Collection and Limitations to Voice AI Research: A National Survey

INTRODUCTION

Accuracy and validity of voice AI algorithms rely on substantial quality voice data. Although commensurable amounts of voice data are captured daily in voice centers across North America, there is no standardized protocol for acoustic data management, which limits the usability of these datasets for voice artificial intelligence (AI) research.

OBJECTIVE

The aim was to capture current practices of voice data collection, storage, analysis, and perceived limitations to collaborative voice research.

METHODS

A 30-question online survey was developed with expert guidance from the voicecollab.ai members, an international collaborative of voice AI researchers. The survey was disseminated via REDCap to an estimated 200 practitioners at North American voice centers. Survey questions assessed respondents' current practices in terms of acoustic data collection, storage, and retrieval as well as limitations to collaborative voice research.

RESULTS

Seventy-two respondents completed the survey of which 81.7% were laryngologists and 18.3% were speech language pathologists (SLPs). Eighteen percent of respondents reported seeing 40%-60% and 55% reported seeing >60 patients with voice disorders weekly (conservative estimate of over 4000 patients/week). Only 28% of respondents reported utilizing standardized protocols for collection and storage of acoustic data. Although, 87% of respondents conduct voice research, only 38% of respondents report doing so on a multi-institutional level. Perceived limitations to conducting collaborative voice research include lack of standardized methodology for collection (30%) and lack of human resources to prepare and label voice data adequately (55%).

CONCLUSION

To conduct large-scale multi-institutional voice research with AI, there is a pertinent need for standardization of acoustic data management, as well as an infrastructure for secure and efficient data sharing.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:1333-1339, 2024.

Effectiveness and Feasibility of Telepractice on Voice Therapy for Female Teachers in Elementary Schools with Self-Reported Voice Disorders

PURPOSE

The purpose of this study is to explore the effectiveness of telepractice in voice intervention for female teachers in elementary schools with self-reported voice disorders.

METHODS

Thirty-five female elementary school teachers with self-reported voice disorders volunteered to participate in the study. They were divided into a telepractice voice intervention group (experimental group N=18) and a face-to-face voice intervention group (control group N=17) based on their employment setting. The exact same treatment protocol was applied to both groups of subjects, except that the intervention group was seen through telepractice, and the control group was seen face-to-face. The treatment protocol includes vocal hygiene education and resonant voice therapy twice a week for a total of eight sessions. Auditory perceptual analysis, acoustic assessment, aerodynamic assessment and self-assessment protocol were conducted before the intervention and one week after the last intervention, and the differences before and after interventions within each group and between groups were compared.

RESULTS

There was no significant difference in baseline data including age, working years, and voice symptoms between the two groups. Both groups showed significant improvement (P<0.05) in all voice assessment before and after the treatment sessions, except for the Voice Handicap Index-10 (VHI-10) assessment. No statistical difference was found in other pre- and post-intervention voice assessment changes between the two study groups. The control group presented higher improvement in the total score, and the two subdomain assessments of physiology and emotion.

CONCLUSIONS

Telepractice voice intervention can effectively improve the voice quality of female teachers in elementary schools, and telepractice therapy can be an effective alternative to face-to-face voice intervention.

Towards Automated Vocal Mode Classification in Healthy Singing Voice-An XGBoost Decision Tree-Based Machine Learning Classifier

Auditory-perceptual assessment is widely used in clinical and pedagogical practice for speech and singing voice, yet several studies have shown poor intra- and inter-rater reliability in both clinical and singing voice contexts. Recent advances in artificial intelligence and machine learning offer models for automated classification and have demonstrated discriminatory power in both pathological and healthy voice. This study develops and tests an XGBoost decision tree based machine learning classifier to develop automated vocal mode classification in healthy singing voice. Classification models trained on mel-frequency cepstrum coefficients, MFCC-Zero-Time Windowing, glottal features, voice quality features, and α-ratios demonstrated 92% average F1-score accuracy in distinguishing metallic and non-metallic singing for male singers and 87% average F1-score for female singers. The model distinguished vocal modes with 70% and 69% average F1-score for male and female samples, respectively. Model performance was compared to human auditory-perceptual assessments of 64 corresponding samples performed by 41 professional singers. The model performed with approximating or subpar performance to human assessors on task-matched problems. The XGBoost gains observed across tested features reveal that the most important attributes for the tested classification problems were MFCCs and α-ratios between high and low frequency energy, with models trained on only these features achieving performance not statistically significantly different from the best tested models. The best automated models in this study do not yet match human auditory-perceptual discrimination but improve on previously reported F1-average accuracies in automated classification in singing voice.

Detecting Mild Phonotrauma in Daily Life

OBJECTIVE

The aim of this study was to gain quantitative insights into the role of daily voice use associated with mild phonotrauma via the Daily Phonotrauma Index (DPI), a measure derived from neck-surface acceleration magnitude (NSAM) and difference between the first two harmonic magnitudes (H1 - H2).

METHODS

An ambulatory voice monitor recorded weeklong voice use for 151 female patients with phonotraumatic vocal hyperfunction (PVH) and 181 female vocally healthy controls. Three laryngologists rated phonotrauma severity from each patient's laryngoscopy. Mixed generalized linear models evaluated the accuracy, sensitivity, and specificity of the original DPI trained on all patients versus a mild DPI version trained on only patients rated with mild phonotrauma. Individual contribution of NSAM and H1 - H2 to each DPI model was also evaluated.

RESULTS

Reliability across the laryngologists' phonotrauma ratings was moderate (Fleiss κ = 0.41). There were 70, 69, and 12 patients with mild, moderate, and severe phonotrauma, respectively. The mild DPI, compared to the original DPI, correctly classified more patients with mild phonotrauma (Cohen's d = 0.9) and less controls (d = -0.9) and did not change in overall accuracy. H1 - H2 contributed less to mild phonotrauma classification than NSAM for mild DPI.

CONCLUSIONS

Compared with the original DPI, the mild DPI exhibited higher sensitivity to mild phonotrauma and lower specificity to controls, but the same overall classification accuracy. These results support the mild DPI as a promising detector of early phonotrauma and that NSAM may be associated with early phonotrauma, and H1 - H2 may be a biomarker associated with vocal fold vibration in the presence of lesions.

LEVEL OF EVIDENCE

Level 4, case-control study Laryngoscope, 133:3094-3099, 2023.

Factors Associated With Loss of Follow-Up in Transgender Patients Receiving Vocal Therapy

OBJECTIVES

Optimal vocal care for transgender patients necessitates regular follow-up. Factors associated with loss of follow-up in voice patients have never been investigated. In this study, we report a case series of transgender patients seeking vocal care at our institution and compare those who were and were not lost to follow-up.

METHODS

Charts of transgender patients diagnosed with gender dysphoria who sought vocal care at our institution from January 2018 through May 2022 were reviewed. A chronological timeline of each patient's care at our vocal clinic was recorded. Loss of follow-up was defined as instances in which patients were not yet satisfied with their vocal outcomes and expressed interest in scheduling a subsequent visit but had not yet done so. Logistic regressions were performed to identify factors associated with loss of follow-up.

RESULTS

Of 73 patients identified, 59 (80.8%) were assigned male at birth, and 72 (98.6%) were non-Hispanic White. Loss of follow-up occurred in 35 (47.9%) patients. Patients who received vocal surgery were significantly less likely to be lost to follow-up (OR: 0.16 (0.03, 0.79); p = 0.03). The availability of telemedicine options for vocal care was protective against loss of follow-up (OR: 0.09 (0.02, 0.44); p = 0.003). Patients who received other non-voice gender-affirming treatments concomitant to their vocal care were more likely to be lost to follow-up (OR: 4.44 (1.35, 14.59); p = 0.01).

CONCLUSION

Loss of follow-up in transgender patients receiving vocal care is common. Providing telemedicine options and encouraging patients to complete vocal care prior to or after receiving other non-voice gender-affirming treatments may help increase rates of follow-up.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:3061-3067, 2023.

Treatment of relapsing functional and organic dysphonia: a narrative literature review

Information about failure and relapses is critical in deciding whether and how to treat a given condition, as well as during patient counselling before therapy. This paper aims to perform a non-systematic review of relapses and failure of dysphonia treatment in the adult population. Studies on failure and relapses after treatment of benign vocal fold lesions, functional dysphonia and neurogenic dysphonia were analysed. The frequency and the duration of follow-up were heterogeneous, and the management of relapses was reported in only a portion of the studies. Relapses after surgical treatment of benign vocal fold lesions ranged between 1% and 58% of cases, and their management was mainly surgical. Rates of relapse after voice therapy for functional dysphonia and spasmodic dysphonia were 12%-88% and 8%-63%, respectively. Rates of relapse after surgical treatment for unilateral and bilateral vocal fold paralysis were 10%-39% and 6%-25%, respectively; treatment was mainly represented by surgical revision. In conclusion, failure and relapses of functional and organic dysphonias after therapy are not rare, but treatment modalities are seldomly reported. The data from this non-systematic review stresses the need for further research in this area.

Efficacy of the Accent Method of Voice Therapy in Professional Voice Users with Minimal Associated Pathological Lesions of the Vocal Folds

Aims

Minimal associated pathological lesions (MAPLs) of the vocal folds are a group of benign disorders commonly related to phonotraumatic conditions and behaviors. Voice therapy (VT) can play a major role in readjusting these maladaptive behaviors and improve overall voice quality, thereby replace surgical intervention in some cases or act as a complementary treatment to enhance the ultimate therapeutic outcomes. This study aims to explore the short-term effect of the Accent method of VT on vocal subjective measures and acoustics in professional users with MAPLs, evaluate the responsiveness of each vocal fold lesion to the VT, and propose a simple model for providing VT to a sector of the population in great need of non-invasive management.

Materials and methods

This analytical cross-sectional included fifty professional voice users with different MAPLs were exposed to multidimensional voice assessments before and after receiving VT training in a tertiary care hospital. These assessments include GRBAS score, Multidimensional Voice Program (MDVP) and validated Arabic version Voice Handicap Index (VHI-30).

Results

This study showed variable positive effects of VT on the different types of MAPLs. Cysts had the highest level of responsiveness to VT in comparison to other lesions, followed by nodules, polyps, contact granuloma, and Reinke's edema.

Conclusions

VT is a substantial solution for managing voice disorders. It should be considered in the management plan of the various types of MAPLs, even in Reinke's edema, which showed the minimum improvement.

Impact of Voice Therapy on Pediatric Patients With Dysphonia and Vocal Nodules: A Systematic Review

One of the most prevalent pediatric ailments around the world is voice disorders. Around 5-million children suffer from voice disorders, and three out of five of them suffer from vocal nodule-induced persistent dysphonia. Nineteen out of 20 otolaryngologists recommend voice therapies for the treatment of pediatric vocal fold nodules. However, the benefits of these therapies still remain to be assessed systematically. The objective of this study is to systematically review the impact of voice therapy (direct and indirect) on pediatric patients with vocal nodules.

In this systematic review of randomized control trials (RCTs), four electronic databases, PubMed, CENTRAL (Cochrane), Science Direct, and Lancet, were explored for the literature survey. The impact of direct and indirect voice therapies on pediatric cases with vocal nodules was reviewed based on the results of the selected articles.

Based on stringent inclusion and exclusion criteria, six articles were selected. All these studies examined the effects of direct and indirect voice therapies on two types of voice disorders, that is, dysphonia and vocal nodules. Only one of the six studies reported significant alleviation of the patient condition post-intervention. However, none of the studies discussed the clinical significance of the interventions.

Three of the six included studies used both direct and indirect voice therapies and reported substantial differences in the data collected before and after the interventions. However, overall, the studies reported more significant improvements in patient conditions. More studies in this domain are still warranted, especially to help understand and define the meaning of the term “effectiveness” with respect to voice therapies.