The Effect of Hemodialysis on Voice: An Acoustic Analysis

Because respiration is part of the well-coordinated process necessary for phonation, this study was conducted with the purpose of analyzing the effect of chronic hemodialysis on voice characteristics of patients with chronic renal failure. A total of 57 patients were recruited for the study, including 31 males and 26 females ranging in age from 16 to 85 years. Patients underwent evaluation of their voice directly before and after hemodialysis using the Kay Elemetric VISI Pitch (Model 330; Kay Elemetric Corporation, Lincoln Park, New Jersey). The vocal acoustic parameters studied include habitual pitch, pitch range, relative average perturbation, shimmer, noise-to-harmonic ratio, voice turbulence index, maximum phonation time, and voice energy. The data were analyzed using the paired t-test for the total sample and the nonparametric test for the female and male subgroups. The total sample analysis showed a statistically significant increase in the habitual pitch after the hemodialyis (p < 0.05), with a borderline increase in the pitch range and maximum phonation time (p < 0.10). In the female group, there was a statistically significant increase in the habitual pitch and a borderline increase in the relative average perturbation. In the male group, there was a significant increase in the habitual pitch with a borderline increase in maximum phonation time. Discussion of the after-mentioned results is presented.     

Acoustic analysis of voice in multiple sclerosis patients

The objective is to investigate the presence of dysphonic symptoms in multiple sclerosis (MS) patients and to compare quantitative acoustic parameters in multiple sclerosis patients and normal individuals. The method of study was an 8-month controlled cross-sectional that was carried out with 106 individuals (30 MS, 76 controls). Both groups included males and females from 20 to 55 years. Exclusion criteria were prior vocal disorder, laryngeal microsurgery, recent endotracheal intubation, tumors, laryngeal, lung or mediastinal metastases, respiratory disease, and other associated neurological diagnoses. For dysphonic symptoms (qualitative variables), associations were assessed using Mantel-Haenszel's chi2 test, with Yates correction or the Fisher exact test when necessary. Statistical significance was set at p< or =0.05. Dysphonia was observed in 70% of MS individuals versus 33% of controls (p=0.01). Association was found between MS and dysphonia (OR: 2.2, CI 95%: 1.13-4.25). Fundamental frequency was higher among MS patients (p=0.01). Fundamental frequency deviation was significantly higher in MS women (but not men) than controls (p=0.00). Jitter was higher in MS men than in all other groups (p=0.00). Results suggest that evaluation and treatment of MS patients should be revised, evaluating voice alterations in relation to other signs. MS seems to intensify gender effect on fundamental frequency deviation, noise, and jitter, with MS women presenting fewer voice variations than men.     

Evaluating the Influence of Warmup on Singing Voice Quality Using Acoustic Measures

Vocal warmup is generally accepted as vital for singing performance. However, only a limited number of studies have evaluated this effect quantitatively. In this study, we evaluated the effect of vocal warmup on voice production, among young female singers, using a set of acoustic parameters. Warmup reduced frequency-perturbation (p < 0.001) and amplitude-perturbation values (p < 0.05). In addition, warmup increased singer's formant amplitude (p < 0.05) and improved noise-to-harmonic ratio (p < 0.05). Tone-matching accuracy, however, was not affected by warmup. The effect of vocal warmup on frequency-perturbation parameters was more evident among mezzo-soprano singers than it was among soprano singers. It was also more evident in the low pitch-range than in the higher pitch-ranges (p < 0.05). The results of this study provide valid support for the advantageous effect of vocal warmup on voice quality and present acoustic analysis as a valuable and sensitive tool for quantifying this effect.     

Acoustic analysis of voice in individuals with amyotrophic lateral sclerosis and perceptually normal vocal quality

Currently, early phonatory changes in amyotrophic lateral sclerosis(ALS) are not well understood. The aim of this study was to compare acoustic parameters of voice in ALS subjects who demonstrated perceptually normal vocal quality on sustained phonation with a control group. We hypothesized that objective analysis of voice would reveal significant differences on specific acoustic parameters of voice compared to the control group. Results revealed statistically significant differences between the two groups on measures related to frequency range and phonatory stability. The findings suggest that early bulbar signs affecting the laryngeal system may be present in patients with ALS before the occurrence of perceptually aberrant vocal characteristics.     

The effect of task on determination of habitual loudness

The purpose of this study was to investigate if there is an effect of task on determination of habitual loudness. Four tasks commonly used to elicit habitual loudness were compared (automatic speech, elicited speech, spontaneous speech, and reading aloud). Participants were adult female speakers (N=30) with normal voice. A one-way analysis of variance (ANOVA) revealed a statistically significant (p < 0.05) effect of task, with post-hoc analyses indicating that there was a statistically significant difference in habitual loudness elicited via automatic versus spontaneous speech (p < 0.05), and automatic speech versus reading aloud (p < 0.001). The issue of how habitual loudness is defined is considered. Implications of the use of one task for determination of habitual loudness are discussed, as is the possibility of a task effect on determination of other clinically useful vocal parameters.     

Changes in Objective Acoustic Measurements and Subjective Voice Complaints in Call Center Customer-Service Advisors During One Working Day

SUMMARY: The aim of this study was to investigate how different acoustic parameters, extracted both from speech pressure waveforms and glottal flows, can be used in measuring vocal loading in modern working environments and how these parameters reflect the possible changes in the vocal function during a working day. In addition, correlations between objective acoustic parameters and subjective voice symptoms were addressed. The subjects were 24 female and 8 male customer-service advisors, who mainly use telephone during their working hours. Speech samples were recorded from continuous speech four times during a working day and voice symptom questionnaires were completed simultaneously. Among the various objective parameters, only F0 resulted in a statistically significant increase for both genders. No correlations between the changes in objective and subjective parameters appeared. However, the results encourage researchers within the field of occupational voice use to apply versatile measurement techniques in studying occupational voice loading.     

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.     

Acoustic Analysis of Voice Quality with or without False Vocal Fold Displacement After Cordectomy

Conventional cordectomy by means of a laryngofissure is one of the therapeutic options for treatment of early glottic cancer. To improve the poor voice quality related to this kind of operation, many authors have developed different techniques to repair the mucosal defect. We analyzed voice quality acoustically and compared it after cordectomy alone and after cordectomy with the reconstruction of the vocal cord in a group of 14 patients affected by T1 glottic carcinoma. All the patients underwent postoperative speech therapy. Three patients who underwent cordectomy with reconstruction showed the presence of diplophonia, while two patients without reconstruction showed the presence of bitonality. The differences of the acoustic parameters (jitter, shimmer, harmonic-to-noise ratio) between the two groups of patients were not statistically significant. Reconstruction of the vocal cord does not seem to improve voice quality after cordectomy even in combination with postoperative speech therapy.     

Prevalence of voice disorders among future teachers

An epidemiological study was conducted in order to find out the prevalence of voice disorders among students studying to be teachers. Vocal symptoms were inquired of 226 students. Their voices were assessed perceptually by a speech therapist and those who had abnormal voice quality or reported several vocal symptoms were referred to a clinical examination by a laryngologist. The results showed that 20% of this population reported two or more vocal symptoms during the previous year and that 19% had an organic voice disorder. This reinforces the need for clinical evaluation of students with vocal symptoms and more vocal training in the teacher education programs.     

A virtual trajectory model predicts differences in vocal fold kinematics in individuals with vocal hyperfunction

A simple, one degree of freedom virtual trajectory model of vocal fold kinematics was developed to investigate whether kinematic features of vocal fold movement confirm increased muscle stiffness. Model simulations verified that increases in stiffness were associated with changes in kinematic parameters, suggesting that increases in gesture rate would affect kinematic features to a lesser degree in vocal hyperfunction patients given the increased levels of muscle tension they typically employ to phonate. This hypothesis was tested experimentally in individuals with muscle tension dysphonia (MTD; N = 10) and vocal nodules (N = 10) relative to controls with healthy normal voice (N = 10) who were examined with trans-nasal endoscopy during a simple vocal fold abductory-adductory task. Kinematic measures in MTD patients were less affected by increased gesture rate, consistent with the hypothesis that these individuals have elevated typical laryngeal muscle tension. Group comparisons of the difference between medium and fast gesture rates (Mann-Whitney, one-tailed) showed statistically significant differences between the control and MTD individuals on the two kinematic features examined (p<0.05). Results in nodules participants were mixed and are discussed independently. The findings support the potential use of vocal fold kinematics as an objective clinical assay of vocal hyperfunction.     

The Towne-Heuer reading passage—A reliable aid to the evaluation of voice

The science of voice evaluation and assessment has profited from technological advancement and objective measurement of voice parameters has become an integral part of the voice examination, however, subjective voice evaluation remains a vital component of any voice examination. The Towne-Heuer Reading Passage was developed in 1970 to provide a reading sample that would facilitate subjective voice evaluation. The reliability of the passage was established using three judges listening to 15 normal Philadelphia speakers and 15 vocal abuse-misuse clients with verified vocal nodules. The frequency of hard glottal attack (HGA) was determined for the two groups and high interjudge and intrajudge correlation was found. A difference in the frequency of HGA was found between the two groups.     

The Towne-Heuer Reading Passage--a reliable aid to the evaluation of voice.

The science of voice evaluation and assessment has profited from technological advancement and objective measurement of voice parameters has become an integral part of the voice examination, however, subjective voice evaluation remains a vital component of any voice examination. The Towne-Heuer Reading Passage was developed in 1970 to provide a reading sample that would facilitate subjective voice evaluation. The reliability of the passage was established using three judges listening to 15 normal Philadelphia speakers and 15 vocal abuse-misuse clients with verified vocal nodules. The frequency of hard glottal attack (HGA) was determined for the two groups and high interjudge and intrajudge correlation was found. A difference in the frequency of HGA was found between the two groups.     

Efficacy of a Behaviorally Based Voice Therapy Protocol for Vocal Nodules

The aim of this study was to assess the effects on vocal function of voice therapy for vocal nodules. Perceptual and physiological progressive changes were examined during a strictly structured, behaviorally based voice therapy protocol in which 11 women with vocal nodules participated. Randomized audio recordings from pretherapy and from each of the therapy approaches (vocal hygiene, respiration, direct facilitation, carryover) were used for perceptual evaluations. Six speech-language pathologists rated ten voice quality parameters. Two evaluation procedures were performed and compared. Interlistener reliability was sufficiently high in both tests. Significant effects of therapy were found for decreased overall dysphonia, press, instability, gratings, roughness, vocal fry, and "scrape." Nonsignificant group effects were found for breathiness, aphonic instances, and lack of sonority. No significant parameter changes occurred between baseline assessment and the completion of the initial (vocal hygiene) phase of therapy. Significant changes were found following the direct facilitation and respiration phases of therapy. Videostroboscopic evaluations made by two laryngologists showed that in no case were the nodules completely resolved. However, the nodules had decreased in size and edema was reduced after therapy for all clients, but one. Combined results suggest: (1) Alterations in vocal function were reflected in perceptual parameters, and (2) the voice therapy had a positive effect on voice quality, vocal status, and vocal function for the majority of the vocal nodule clients.     

Analysis of Vocal-fold Vibrations from High-Speed Laryngeal Images Using a Hilbert Transform-Based Methodology

This paper presents a Hilbert transform-based approach to analyze vocal fold vibrations in human subjects exhibiting normal and abnormal voice productions. This new approach is applied to the analysis of glottal area waveform (GAW) and is capable of providing useful information on the vocal fold vibration. The GAW is extracted from high-speed laryngeal images by delineating the glottal edge for each image frame. An analytic signal is generated through the Hilbert transform of the GAW, which yields a recognizable pattern of the vocal fold vibration in the analytic phase plane. The vibratory pattern is comprehensive and can be correlated with specific voice conditions. Quantitative measures of the glottal perturbation are introduced using the analytic amplitude and instantaneous frequency obtained from the analysis. Examples of clinical voice recordings are used to evaluate and test the effectiveness of this approach in providing qualitative representation and quantitative characteristics of vocal fold vibratory behavior. The results demonstrate the potential of using this new analytical tool incorporated with the high-speed laryngeal imaging modality for clinical voice assessment.     

The Influence of Auditory Feedback and Vocal Rehabilitation on Prelingual Hearing-Impaired Individuals Post Cochlear Implant

ObjectiveTo verify changes in the perceptual and acoustic vocal parameters in prelingual hearing-impaired adults with cochlear implants after vocal rehabilitation.HypothesisAuditory feedback restoration alone after cochlear implant is not enough for vocal adjustments. A targeted and specific voice therapy intervention is required.Study DesignProspective and pre–post repeated measures design.MethodsTwenty literate adults with severe to profound prelingual bilateral sensorineural hearing loss participated in the study; individuals were implanted late and were fluent users of oral language. Ages ranged from 17 to 48 years. All individuals presented normal results in laryngoscopy, and hearing thresholds with the cochlear implant were over 40 dB HL. Individuals were randomly distributed into two groups: Group 1 (treatment group) and Group 2 (control group), both with ten patients each, five men and five women, matching mean age and hearing deprivation time before the cochlear implantation. Patients from Group 1 underwent a protocol of vocal therapy including 12 individual sessions with the same clinician. Group 2 only underwent vocal recordings. The vocal recordings occurred before and after the participation in the therapy protocol for Group 1 and after the same period, 3 months later, without any intervention, for Group 2. The recording sessions used the Consensus Auditory-Perceptual Evaluation of Voice protocol sentence reading and emission of sustained vowel /a/. Auditory-perceptual evaluation of voices was performed by three judges, and the acoustical analysis used the Praat program.ResultsStatistically significant reductions in the overall vocal degree, vocal instability, and degree of resonance change were observed after vocal rehabilitation in Group 1. Statistically, individuals from Group 1 did not differ in regard to the modification of acoustic parameters. Group 2 did not present significant changes in any of the analyzed parameters.ConclusionsThe cochlear implanted adults submitted to vocal rehabilitation presented changes in the auditory-perceptual parameters, with reduction of the overall voice severity, vocal instability, and degree of resonance after vocal intervention. There were no changes in the acoustic parameters in the implanted prelingual hearing-impaired adult subjects.     

Mild Vocal Fold Paresis: Understanding Clinical Presentation and Electromyographic Findings

The implications of mild vocal fold hypomobility are incompletely understood. This study describes the clinical, electromyographic, and probable etiologic findings in patients who presented with complaints of dysphonia and whose physical examination revealed vocal fold paresis as a factor possibly contributing to their voice complaints. A retrospective chart review of all patients who presented to a tertiary laryngology referral center over a 13-month period, who had a clinical diagnosis of mild vocal fold hypomobility and who underwent laryngeal electromyography, were included in the study. A total of 22 patients completed the medical evaluation of their voice complaint. Of these patients, 19 (86.4%) were found to have evidence of neuropathy on laryngeal electromyography. The clinical picture indicated the following probable origins for the vocal fold paresis: goiter/thyroiditis (7/22 or 31.8%), idiopathic (4/22 or 18.2%), viral neuritis (4/22 or 18.2%), trauma (3/22 or 13.6%), and Lyme's disease (1/22 or 4.5%). This article describes the clinical entity of mild vocal fold hypomobility and associated flexible laryngoscopic, rigid strobovideolaryngoscopic, and laryngeal electromyographic findings.     

A Preliminary Study of Vocal Health Among Collegiate A Cappella Singers

ObjectiveCollegiate a cappella groups have grown significantly in popularity and prominence; however, there have been few studies that evaluate the vocal health of this subgroup of young singers. The objective of this preliminary study was to conduct a multiparametric evaluation of the vocal health characteristics of a sample of collegiate a cappella singers. We further tested whether differences in vocal health assessments exist between a cappella singers with and without vocal training and trained collegiate singers who do not participate in a cappella groups.Study designPoint prevalence study.MethodsForty-one collegiate singers participated in this study. Participants were divided into the following three groups: trained singers (TS), trained a cappella singers (ATS), and untrained a cappella singers (AUS). Participants were administered a set of surveys to assess self-perception of singing voice health and perceived access and attitudes toward voice-related health care. Acoustic and laryngoscopic assessments of participant's speaking and singing voice was performed and validated vocal health questionnaires administered as a means to objectively evaluate for the presence of voice problems.ResultsOverall, 87.5% of the ATS and 60% of the AUS groups reported experiencing problems with their singing voice. However, no vocal abnormalities were detected during laryngoscopic and acoustic assessments. Furthermore, minimal differences between any of the measured vocal health parameters were observed between the TS, ATS, and AUS groups.ConclusionCollectively, a high percentage of collegiate a cappella singers with and without vocal training report singing voice problems. However, our sample of a cappella singers did not have increased singing voice problems as compared to vocally trained collegiate singers not in a cappella groups. We did find that a cappella singers may be more inclined to seek information about maintaining a healthy singing voice from their fellow musicians as opposed to singing teachers or other voice health professionals. Singing teachers, otolaryngologists, and speech-language pathologists may need to play a more active role in educating a cappella singers regarding maintaining good vocal health.     

Management of Vocal Fold Scar with Autologous Fat Implantation: Perceptual Results

Vocal fold scar disrupts the mucosal wave and interferes with glottic closure. Treatment involves a multidisciplinary approach that includes voice therapy, medical management, and sometimes surgery. We reviewed the records of the first eight patients who underwent autologous fat implantation for vocal fold scar. Information on the etiology of scar, physical findings, and prior interventions were collected. Videotapes of videostroboscopic findings and perceptual voice ratings [Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS)] were randomized and analyzed independently by four blinded observers. Etiology of scar included mass excision (7), vocal fold stripping (3), congenital sulcus (2), and hemorrhage (1). Prior surgical procedures performed included thyroplasty (1), autologous fat injection (9), excision of scar (2), and lysis of adhesions (2). Strobovideolaryngoscopy: Statistically significant improvement was found in glottic closure, mucosal wave, and stiffness (P = 0.05). Perceptual ratings (GRBAS): Statistically significant improvement was found in all five parameters, including overall Grade, Roughness, Breathiness, Asthenia, and Strain (P = 0.05). Patients appear to have improved vocal fold function and quality of voice after autologous fat implantation in the vocal fold. Autologous fat implantation is an important adjunctive procedure in the management of vocal fold scar, and a useful addition to the armamentarium of the experienced phonomicrosurgeon.     

Perceptual and Acoustic Assessment of Voice Pathology and the Efficacy of Endolaryngeal Phonomicrosurgery

Values for acoustic voice measurements were obtained from 88 normal individuals and 98 pathological cases of mass lesions of vocal fold and 50 cases of unilateral vocal fold paralysis. Overall, all items reflecting perturbations of pitch and amplitude as well as glottal noise were significantly higher in the groups of patients compared with the normal group. The measurement of normalized noise energy (NNE) was found to be an optimum parameter for discrimination of normal/abnormal voices. The voices of patients with vocal fold nodules and vocal fold polyps were analyzed before endolaryngeal phonomicrosurgery (EPM) and 2 weeks after. Statistically significant (p < 0.01) improvement was achieved both in perceptual and acoustic analysis. EPM resulted in a significant decrease of mean jitter, shimmer, and NNE. Clinically, these measures provided documentable and measurable evidence of vocal function and were helpful for comparing patients with normal speakers. They also were useful for a thorough documentation of patient's voice pathology and for evaluation of the presurgical and postsurgical voice status.     

Laryngostroboscopic, Acoustic, and Environmental Characteristics of High-Risk Vocal Performers

Vocal performance often requires excessively high vocal demand. In particular “high-risk” performers, a group of individuals who use their voices at their maximum effort level, are often exposed to unique vocal abuse characteristics which include high environmental and performance demands and inconsistencies of cast performance. Three categories of high-risk performers were studied: musical theater, choral ensemble, and street theater. Musical theater performers produce a Broadway, West End “belting” style voice. Street theater performers use a high-energy pitch varying dialogue in order to imitate a desired character voice. Choral ensemble performance requires group cohesion and blending of four-part harmony. The melodies require sustained vocal durations within each of the respective registers. For each of these studied groups vocal tasks of sustained production of /i/ and /a/ were subjected to analysis. Acoustic measures included fundamental frequency, standard deviation of fundamental frequency, jitter percent, shimmer percent, and noise-to-harmonic ratio. Laryngostroboscopic parameters were assessed during sustained /i/. Environmental acoustic sound field measurements were made using an A weighting and linear weighting sound pressure level. These weightings were used to describe noise levels and vocal output, respectively, within the performance environments. Results of the analysis suggest that high-risk performers are a unique performance type defined by distinctive, acoustic, laryngostroboscopic, and environmental characteristics.