Outcome of laryngeal manual therapy in four Dutch adults with persistent moderate-to-severe vocal hyperfunction: a pilot study

A relatively new management strategy for the treatment of voice disorders is the use of laryngeal manual therapy. The main purpose of the present pilot study is to document the outcome of vocal quality after a well-defined laryngeal manual therapy (LMT) program. Four Dutch professional voice users with a persistent moderate or severe muscle tension dysphonia were studied pretreatment (1 week before LMT) and posttreatment (1 week) after completion of manual therapy (25 sessions). These subjects had received several months of traditional voice therapy, without any success. To measure and compare, the effect of LMT objective and subjective assessment techniques were used. Perceptual voice assessment included a perceptual rating of the voice using the GRBAS scale. Furthermore, the vocal quality in this population was modeled by means of the Dysphonia Severity Index (DSI). All of the subjects selected for LMT showed improvement in perceptual vocal quality and DSI values. As the DSI is a weighted variable including aerodynamic and acoustic measures, small improvements (closer to 5) are very indicative of vocal quality improvement.¹ The use of LMT in professional voice users with persistent moderate-to-severe muscle tension dysphonia, especially in some subjects who have not responded to traditional voice therapy, is supported by this pilot study.     

Analysis and Evaluation of a Voice-Training Program in Future Professional Voice Users

The goal of this study is to analyze and evaluate the effectiveness of a voice-training program. Twenty-three professional voice users received voice training for 2 years and vocal hygiene education for 1 year. The voice-training program consisted of lectures, technical workshops, and vocal coaching. The European Laryngological Society (ELS) protocol, including the Dysphonia Severity Index (DSI) and the Voice Handicap Index (VHI), was applied before and after, respectively, 9 and 18 months of voice training. A questionnaire on daily habits was presented at study onset and after 18 months. The DSI improvement is more significant after 9 months (P=0.005) than it is after 18 months (P=0.2). On the other hand, the perceptual evaluation remained unchanged after 9 months, whereas it improved significantly after 18 months. The results of the daily habit questionnaire are disturbing: the prevalence of smoking, vocal abuse, stress, and late meals were not influenced by the lectures and remained high. This study emphasizes the need for a well-organized voice-training program that is most effective after 9 months. Regarding the low effectiveness of the vocal hygiene program, the concept needs revision.     

A Comparison of Trained and Untrained Vocalists on the Dysphonia Severity Index

The purposes of this study were (1) to compare trained and untrained singers on the Dysphonia Severity Index (DSI) and its component measures, and (2) to contribute to normative DSI data for trained singers. This study included 36 untrained participants (15 males and 21 females) and 30 participants (15 males and 15 females) with singing experience between the ages of 18 and 30 years. Measures of maximum phonation time (MPT), highest phonational frequency, lowest intensity, and jitter were obtained for each subject and incorporated into the previously published multivariate DSI formula. Results indicated that vocally trained subjects have significantly higher DSI scores than untrained subjects (mean DSI: 6.48 vs 4.00, respectively), with significant differences observed between trained and untrained groups for three of the four components of the DSI (F₀ high; I low; jitter). The findings of this study are consistent with previous reports that indicate significant increases in the DSI with vocal training, and with various studies that have observed increased vocal capability in trained singers versus their untrained counterparts. The results of this study indicate that alternative normative expectations for the DSI may need to be taken into account when using the DSI with patients who have participated in directed vocal training, such as choral participation and voice/singing lessons.     

Validation of the Dysphonia Severity Index in the Dr. Speech Program

PurposeThe Dysphonia Severity Index (DSI) is an objective multiparameter index of voice quality that measures and describes overall voice quality. Some studies have suggested that the reliability of devices for DSI measurement should be examined. We explored the feasibility of DSI measurements using the Dr. Speech (DRS) device, verified its effectiveness for clinical voice measurements and intradevice reliability, and examined the correlation between the DSI and self-evaluations of voice problems.MethodsSeventy adult participants (including individuals with voice problems and healthy adults) underwent objective and subjective voice assessments. These data were then used to establish a DSI_DRS model and test the intradevice (DRS device and Praat software) reliability. The clinical validation of the DSI_DRS was conducted by measuring the DSI of six other participants and comparing the observed and predicted perceived voice quality as expressed by the G score (of the GRBAS scale). Moreover, the relationship between the DSI measurements and participants’ self-evaluations of voice problems was investigated by analyzing the correlation between the DSI and the Voice Handicap Index (VHI).ResultsThe DSI_DRS discriminated 80% of participants’ voice quality ratings. There were strong correlations between the DSI and variables measured by the DRS device and Praat software. Furthermore, there was no significant correlation between the DSI_DRS and VHI.ConclusionThe DRS device can perform DSI measurements. Objective voice measurements and perceptual voice ratings reflected different aspects of vocal function and its effects. These factors should be considered in clinical practice settings.     

Genetics of Vocal Quality Characteristics in Monozygotic Twins: A Multiparameter Approach

The main purpose of this study was to determine the vocal quality characteristics among the 45 monozygotic cotwins (MT). As the performance of the voice is related to several genetically determined anatomical and physiological factors, the authors hypothesized that the vocal characteristics and the overall vocal quality by means of the Dysphonia Severity Index (DSI) will be identical in MT. An additional objective of this study was to determine whether sex and age influence vocal similarities in MT and to compare the voice characteristics of MT with the normative data of unrelated peers. As more environmental factors influence the aging of the voice, age-related differences were expected. No sex-related differences were expected. Subjective and objective assessment techniques determined the vocal quality. No significant differences were obtained, and most comparisons resulted in significant correlation coefficients. For the acoustic parameters jitter and shimmer only, no significant correlation coefficients could be obtained. It is clear that the perceptual voice characteristics, the laryngeal aerodynamic measurements of maximum phonation time (MPT), the vocal performances, and the overall vocal quality by means of the DSI are similar in MT. These vocal characteristics are not influenced either by the subjects' age or sex and are situated within the normative range of unrelated peers. To what extent other aspects (environment, anxiety, tension, etc) might play a role in the acoustical dimensions regarding frequency and amplitude perturbation, which were in the normal range, is a subject of further research.     

The Relationship Between Perceptual Evaluation and Objective Multiparametric Evaluation of Dysphonia Severity

SUMMARY: The purpose of this study was to investigate the usefulness of the Dysphonia Severity Index (DSI) as an objective multiparametric measurement in assessing dysphonia. The DSI was compared with the score on Grade of the GRBAS scale. Investigated was also whether the DSI is related to severity of dysphonia, which was represented by different diagnosis groups. Furthermore, it was investigated whether the DSI can differentiate between a group of patients and a control group. A total of 294 patients with different voice pathologies were included. A control group consisted of 118 volunteers without any voice complaints. The voices of all participants were perceptually evaluated on Grade, and the DSI was measured. The groups of patients with voice complaints have a lower DSI and higher scores on Grade than the control group. The DSI was significantly lower when the score on Grade was higher. The DSI discriminates between patients with nonorganic voice disorders, vocal fold mass lesions, and vocal fold paresis/paralysis. To determine whether the DSI discriminates between patients and controls, the sensitivity and specificity for different DSI cutoff points were calculated. With a DSI cutoff of 3.0, maximum sensitivity (0.72) and specificity (0.75) were found. We conclude that the DSI is a useful instrument to objectively measure the severity of dysphonia.     

Poor Voice Quality in Future Elite Vocal Performers and Professional Voice Users

The voice quality of 86 occupational voice users, i.e., students of a high school for audiovisual communication, was assessed by means of a multidimensional test battery containing: the GRBAS scale, videolaryngostroboscopy, maximum phonation time, jitter, lowest intensity, highest frequency, dysphonia severity index (DSI), and voice handicap index (VHI). In a questionnaire on daily habits the prevalence of smoking, eating habits, and vocal abuse were recorded. A comparison of the voice characteristics of the future occupational voice users with a control group revealed significant differences. The results of the VHI and the DSI of these students revealed significantly worse scores than the score of a control group characterized by no vocal complaints. Moreover, the questionnaire on daily habits showed that the future elite vocal performers and professional voice users take less precautions for the care of their voices. These findings support the importance of a good balanced vocal coaching.     

Outcome of Resonant Voice Therapy for Female Teachers With Voice Disorders: Perceptual, Physiological, Acoustic, Aerodynamic, and Functional Measurements

Teachers have a high percentage of voice problems. For voice disordered teachers, resonant voice therapy is hypothesized to reduce voice problems. No research has been done on the physiological, acoustic, and aerodynamic effects of resonant voice therapy for school teachers. The purpose of this study is to investigate resonant voice therapy outcome from perceptual, physiological, acoustic, aerodynamic, and functional aspects for female teachers with voice disorders. A prospective study was designed for this research. The research subjects were 24 female teachers in Taipei. All subjects received resonant voice therapy in groups of 4 subjects, 90 minutes per session, and 1 session per week for 8 weeks. The outcome of resonant voice therapy was assessed from auditory perceptual judgment, videostroboscopic examination, acoustic measurements, aerodynamic measurements, and functional measurements before and after therapy. After therapy the severity of roughness, strain, monotone, resonance, hard attack, and glottal fry in auditory perceptual judgments, the severity of vocal fold pathology, mucosal wave, amplitude, and vocal fold closure in videostroboscopic examinations, phonation threshold pressure, and the score of physical scale in the Voice Handicap Index were significantly reduced. The speaking Fo, maximum range of speaking Fo, and maximum range of speaking intensity were significantly increased after therapy. No significant change was found in perturbation and breathiness measurements after therapy. Resonant voice therapy is effective for school teachers and is suggested as one of the therapy approaches in clinics for this population.     

Psychogenic Voice Disorders in Performers: A Psychodynamic Model

Psychogenic voice disorders are not infrequently encountered in the busy voice clinic. A clinician-friendly psychodynamic model and a multidisciplinary management approach are presented which have proven helpful for our voice team and our patients. In essence the formulation revolves around an “event” occurring, which may be either organic or psychological in nature. The ensuing dysphonia then leads to emotional consequences which in turn have physical consequences on the vocal tract. The situation can become reinforcing and illness behaviors develop. Elucidating this event/process to the patient improves the likelihood of a successful long-term outcome. The diagnostic and management roles of the various team members are discussed.     

Laryngeal adduction in resonant voice

The primary question in this study was whether subjects with nodules and subjects with healthy larynges would produce “resonant voice” with a similar laryngeal configuration. A second question regarded whether the electroglottographic closed quotient (EGG CQ) could be used to noninvasively distinguish resonant from other voice types. Twelve adult singers and actors served as subjects, including 6 persons with healthy larynges and 6 persons with nodules. Performers were used as an attempt to maximize token validity and stability. Subjects produced repeated tokens of resonant, pressed, normal, and breathy voice during sustained vowels. Laryngeal adduction was directly estimated using blinded, ordinal, visual-perceptual ratings based on videoscopic views of the larynx. EGG CQs were further calculated based on separate trials. The perceptual ratings indicated that subjects in both groups produced resonant voice with a barely adducted or barely abducted laryngeal configuration that was distinct from configurations for pressed and breathy (but not normal) voice. Previous literature suggests that this configuration may be relevant in many cases of voice therapy (I). Average CQs distinguished resonant from pressed voice, but inconsistently distinguished resonant from breathy voice. Further CQs were reliably different across healthy subjects and subjects with nodules. Thus, the utility of this measure to noninvasively estimate resonant voice may be limited, particularly without ongoing subject-specific calibration procedures.     

A Randomized Treatment-Placebo Study of the Effectiveness of Acupuncture for Benign Vocal Pathologies

Acupuncture is a widely accepted treatment option for many medical ailments in China. Some reports claim that acupuncture is effective for treating dysphonia associated with benign pathological tissue changes. However, many of these reports are based on anecdotal evidence that lacks a scientific experimental design. The objective of this study was to investigate the effectiveness of intensive acupuncture therapy for dysphonias associated with benign pathological changes with a randomized, control design. Twenty-four subjects aged between 19 and 51 years were randomly assigned to either an experimental group or a placebo group. The experimental group received acupuncture on acupoints Renyin (Stomach Channel 9), Lieque (Lung Channel 7), and Zhaohai (Kidney Channel 6), which are all related to improving throat problems and vocal function, whereas the placebo group received acupuncture on acupoints Houxi (Small Intestine Channel 3) and Kunlun (Bladder Channel 60), which are not related to voicing. All subjects received 10 intensive acupuncture sessions within a 20-day period. Acoustic analysis of voice range profile, perceptual analysis of voice quality, and self-perceptions of quality-of-life (QOL) measurement by patients were the outcome measures for determining treatment efficacy. Results revealed significant improvement in the treatment group in all three aspects when compared with the placebo group. The acupuncture effect was maintained into the second week after the completion of acupuncture treatment.     

The Effectiveness of a Voice Treatment Approach for Teachers With Self-Reported Voice Problems

SUMMARY: Teachers are considered the professional group most at risk of developing voice-problems, but limited treatment effectiveness evidence exists. We studied prospectively the effectiveness of a 6-week combined treatment approach using vocal function exercises (VFEs) and vocal hygiene (VH) education with 20 teachers with self-reported voice problems. Twenty subjects were randomly assigned to a no-treatment control (n = 11) and a treatment group (n = 9). Fibreoptic endoscopic evaluation was carried out on all subjects before randomization. Two self-report voice outcome measures were used: the Voice-Related Quality of Life (VRQOL) and the Voice Symptom Severity Scale (VoiSS). A Voice Care Knowledge Visual Analogue Scale (VAS), developed specifically for the study, was also used to evaluate change in selected voice knowledge areas. A Student unpaired t test revealed a statistically significant (P < 0.05) improvement in the treatment group as measured by the VoiSS. There was not a significant improvement in the treatment group as measured by the V-RQOL. The difference in voice care knowledge areas was also significant for the treatment group (P < 0.05). This study suggests that a voice treatment approach of VFEs and VH education improved self-reported voice symptoms and voice care knowledge in a group of teachers.     

Influence of glottal closure configuration on vocal efficacy in young normal-speaking women

Posterior closure insufficiency of the glottis is often mentioned in connection with permanent voice disorders. Recently published studies have revealed that an incomplete closure of the glottis can be found also in normal-speaking voices, especially in women. However, the effect of glottal closure configuration on vocal efficacy is not sufficiently clarified. The purpose of this study was to determine the effect of glottal closure configuration on singing and speaking voice characteristics. Overall, 520 young female normal-speaking subjects were examined by videostroboscopy for different phonation conditions in the combination of soft, loud, low, and/or high phonation and by voice range profile measurements. According to the videostroboscopic analysis, the subjects were subdivided into four groups: complete closure of the vocal folds already in soft phonation (group 1), closure of the vocal fold with increasing intensity (group 2), persistent closure insufficiencies despite increasing intensity (group 3), and hourglass-shaped closure in subjects with vocal nodules (group 4). Subjects in which the glottal closure could not be evaluated sufficiently were subclassified into group 5 (missing values).

Selected criteria of the singing and speaking voice were evaluated and statistically processed according to the mentioned subclassification. Group 1 reached significantly the highest sound pressure levels (SPL_max) for the singing voice as well as for the shouting voice. Group 3 showed a limited capacity to increase the intensity of the singing and speaking voice. The results gathered in this study objectify the relationship of insufficient glottal closure and reduced vocal capabilities. As long as no conclusive data on long-term consequences of insufficient glottal closure are available, a prophylactic improvement of the laryngeal situation especially in female professional voice users by voice therapy should be recommended.     

Vocal quality characteristics in children with cleft palate: a multiparameter approach

The main purpose of the present study was to examine the vocal quality and to investigate the effects of gender on vocal quality in 28 children with a unilateral or bilateral cleft palate. In this study, the vocal quality was determined using videolaryngostroboscopic and perceptual evaluations, aerodynamic, voice range, acoustic, and dysphonia severity index (DSI) measurements. The DSI is based on the weighted combination of four voice measurements and ranges from +5 to -5 for, respectively, normal and severely dysphonic voices. Additional objectives were to compare the vocal quality characteristics of children with cleft palate with the available normative data and to investigate the impact of the cleft type on vocal quality. Gender-related vocal quality differences were found. The male cleft palate children showed an overall vocal quality of +0.62 with the presence of a perceptual slight grade of hoarseness and roughness. The female vocal quality had a DSI value of +2.4 reflecting a perceptually normal voice. Irrespective of the type of cleft, all subjects demonstrated a significantly lower DSI-value in comparison with the available normative data. The results of the present study have provided valuable insights into the vocal quality characteristics of cleft palate children.     

Objective Voice Quality Analysis Before and After Onset of Unilateral Vocal Fold Paralysis

This study was designed to investigate objective voice quality measurements in unilateral vocal fold paralysis (UVFP) by eliminating intersubject variability. To our knowledge this is the first report objectively analyzing paralytic dysphonia as compared to the same voice before onset of UVFP. The voices of two male subjects were prospectively recorded before and after the onset of iatrogenic UVFP (thoracic surgery).The following acoustic measurements of the vowel /a/ were performed using the CSL and MDVP (Kay Elemetrics): jitter, shimmer, harmonics-to-noise ratio, cepstral peak prominence, the relative energy levels of the first harmonic, the first formant and the third formant, the spectral slope in the low-frequency zone (0-1 kHz and 0-2 kHz), and the relative level of energy above 6 kHz. Distribution of spectral energy was analyzed from a long-term average spectrum of 40 seconds of text. Laryngeal aerodynamic measurements were obtained for one patient before and after onset of paralysis using the Aerophone II (Kay Elemetrics). Pitch and amplitude perturbation increased secondary to UVFP, while the harmonics-to-noise ratio and the cepstral peak prominence decreased. A relative increase in the mid-frequency and high-frequency ranges and a decrease in the low-frequency spectral slope were observed. Mean airflow rate and intraoral pressure increased, and glottal resistance and vocal efficiency decreased secondary to UVFP. The findings of this self-paired study confirm some but not all the results of previous studies. Measures involving the fundamental and the formants did not corroborate previous findings. Further investigation with vocal tract modeling is warranted.     

Etiology and treatment of psychogenic voice disorder:Results of a follow-up study of thirty patients

It is generally accepted that psychogenic voice disorder (PVD) is aresult of psychosocial stress; however, systematic studies of etiological factors in this condition are few. Furthermore, although immediate effects of therapy are estimated to be good, relapses are frequent, and the long-term effects of therapy are not known. The present prospective and longitudinal study on 30 patients was thus focused on possible etiological factors, the course of therapy, and the long-term results of therapy for PVD. The results indicate that interpersonal conflicts related to family and work are of basic importance in precipitating this condition. PVD is interpreted as a specific disorder of verbal emotional expression. Our therapy model in which vocal exercises are performed, together with training of communicative skills, seems rewarding. Relapses were not reported in 88% of the patients during the followup period of 1.9-8.4 years after therapy.     

Study of the elderly females'' voice by phonetography

This study was carried out to investigate the voice characteristics of 40 healthy females with no voice disorders, ranging in age from 60 to 84 years (X = 68.2+/-5.74 years). Measurements over all the entire phonational range were obtained by phonetography. The subjects were asked to sustain the vowel /a/ in modal register for a minimum of 5 seconds in the highest and lowest intensities after hearing the semitones C, E, G, and A, over all phonational ranges. The results indicated expansion of the low and reduction of high ends of the pitch range, decrease of the pitch numbers of the vocal range, restriction of the lowest and highest limits of the intensity, and reduction of either the maximum phonational range and the phonetogram area. The phonetography technique has shown efficacy to investigate the voice characteristics of elderly females.     

The Effectiveness of Group Therapy for Students With Mild Voice Disorders: A Controlled Clinical Trial

Previous studies of students studying to be teachers have indicated that these students commonly have voice disorders. Ideally, voice disorders should be treated before students start their work as teachers, but the resources for this treatment are often limited. This study examines whether group voice therapy is effective for teacher students. Accordingly, 20 teacher students with mild voice disorders received group voice therapy (in three small groups), whereas 20 students with similar voice disorders served as a control group and consequently did not receive voice therapy. Two out of three outcome measures (perceptual evaluation of voice quality and a questionnaire on the occurrence of vocal symptoms) indicated significant changes in the treatment group compared with the control group. No differences between groups were noted in the laryngeal status. The results suggest that group voice therapy seems to be an effective method to treat students with mild voice disorders.     

Treatment Outcomes for Professional Voice Users

Professional voice users comprise 25% to 35% of the U.S. working population. Their voice problems may interfere with job performance and impact costs for both employers and employees. The purpose of this study was to examine treatment outcomes of two specific rehabilitation programs for a group of professional voice users. Eighteen professional voice users participated in this study; half had complaints of throat pain or vocal fatigue (Dysphonia Group), and half were found to have benign vocal fold lesions (Lesion Group). One group received 5 weeks of expiratory muscle strength training followed by six sessions of traditional voice therapy. Treatment order was reversed for the second group. The study was designed as a repeated measures study with independent variables of treatment order, laryngeal diagnosis (lesion vs non-lesion), gender, and time. Dependent variables included maximum expiratory pressure (MEP), Voice Handicap Index (VHI) score, Vocal Rating Scale (VRS) score, Voice Effort Scale score, phonetogram measures, subglottal pressures, and acoustic and perceptual measures. Results showed significant improvements in MEP, VHI scores, and VRS scores, subglottal pressure for loud intensity, phonetogram area, and dynamic range. No significant difference was found between laryngeal diagnosis groups. A significant difference was not observed for treatment order. It was concluded that the combined treatment was responsible for the improvements observed. The results indicate that a combined modality treatment may be successful in the remediation of vocal problems for professional voice users.     

Voice profiles and standard voice profile of untrained children

Voice profiles were taken of 277 healthy children between the ages of 5 and 14 years. The measured phonetograms were grouped according to sex and years of age. In each group, the means and standard deviations of maximal and minimal volume of each frequency were calculated. The median was used to establish the upper and lower limits of the voice range of each group. No age-dependent changes of the group voice profiles were shown in the groups of 7 to 10 year olds. Out of that emerged a standard childhood voice profile of the untrained voice. After age 10, an increase of the dynamic range over the lowest frequencies was found. Because of the voice changes in puberty, a profile for 13- and 14-year-old boys could not be established.