Objective and Subjective Evaluation of Voice Quality in Multiple Sclerosis

The aim of this comparative, controlled, cross-sectional study is to evaluate the voice quality in patients with multiple sclerosis (MS) by subjective and objective methods. Female patients with MS (n=27) and age- and sex-matched healthy controls (n=27) were included in this study. Vocal functions were evaluated by a multidimensional set composed of videolaryngostroboscopic examination, acoustic analysis, and subjective measurements (GRBAS and "Voice Handicap Index"). Jitter percent, shimmer percent, and soft phonation index (SPI) values were higher in MS patients compared to controls (Jitt, P=0.001; Shim, P=0.033; SPI P<0.0001). Maximum phonation time was significantly shorter for MS patients compared to controls (P<0.0001). Stroboscopic examination revealed that 16 out of 27 MS patients have a "posterior chink" as glottic closure pattern with higher SPI values (40%). Noise to harmonic ratio (NHR) and mean fundamental frequency (F0) values were similar for MS and control groups (NHR, P=0.737; F0, P=0.976). In this study, most of the MS patients had dysphonia due to weakness of voice. MS tends to worsen acoustic parameters including fundamental frequency, SPI, and jitter values. These results are consistent with the more asthenic voice quality observed in MS group.     

Acoustic voice analysis in patients with essential tremor

To quantify several acoustic features of the voice in patients with essentialtremor (ET), 28 patients and 28 age- and sex-matched controls were studied. ET severity was assessed with the rating scale for tremor of Fahn, Tolosa, and Marín. The Computerized Speech Lab 4300 program (Kay Elemetrics) was used. Two-second samples of a sustained /a/ and a sentence were captured with a microphone and laryngograph equipment. Measures included fundamental frequency (F₀), frequency perturbation (fitter, Koike algorithm), intensity perturbation (shimmer, Horii algorithm), and harmonic-to-noise ratio (H/N, Yumoto algorithm) of the vowel /a/, and the frequency and intensity variability of the sentence, phonational range, and dynamic range at the natural frequency, maximum phonational time, and s/z ratio. All subjects underwent indirect laryngoscopy and/or laryngeal fibroscopy. When compared with controls, ET patients showed higher jitter, lower H/N ratio (the last one only with laryngographic signal), of the vowel /a/, lower frequency variability in the microphonc signal, lower intensity variability in the laryngographic signal of the sentence, and significantly lower dynamic range at natural frequency of phonation. ET patients reported higher frequency of the presence of high voice intensity, tremor, and struggle. Several acoustic parameters were influenced by the severity of the disease, including shimmer, jitter, H/N ratio, frequency variability of the sentence, and s/z ratio, although neither of the acoustic analysis values or the phonetometric measurements were affected by the presence of voice tremor or by a successful pharmacological treatment of ET.     

Validity and Reliability of the Reflux Symptom Index (RSI)

Laryngopharyngeal reflux (LPR) is present in up to 50% of patients with voice disorders. Currently, there is no validated instrument that documents symptom severity in LPR. We developed the reflux symptom index (RSI), a self-administered nine-item outcomes instrument for LPR. The purpose of this investigation was to evaluate the psychometric properties of the RSI. For validity assessment, 25 patients with LPR were evaluated prospectively before and six months after b.i.d. treatment with proton pump inhibitors (PPI). Each patient completed the RSI as well as the 30-item voice handicap index (VHI). For reliability assessment, the study patients were given the RSI on two separate occasions before the initiation of treatment. Normative RSI data were derived from 25 age-matched and gender-matched controls taken from an existing database of asymptomatic individuals without any evidence of LPR. The mean RSI (+/- standard deviation) of patients with LPR improved from 21.2 (+/- 10.7) to 12.8 (+/- 10.0), and the mean VHI improved from 52.2 (+/- 24.7) to 41.5 (+/- 25.0) after 6 months of therapy (p = 0.001 and 0.065, respectively). Of the three VHI subscales (emotional, physical, functional), only the functional subscale improved significantly (p = 0.037). Patients who experienced a five point or better improvement in RSI were 11 times more likely to experience a five-point improvement in VHI (95% confidence interval = 1.7, 76.8). For reliability assessment, the first and second pretreatment RSIs were 19.9 (+/- 11.1) and 20.9 (+/- 9.6), respectively (correlation coefficient = 0.81, p < 0.001). The single-item correlation coefficients ranged from 0.41 to 0.91 (p < 0.05 for all items). The mean pretreatment RSI in patients with LPR was significantly higher than controls (21.2 versus 11.6; p < 0.001). The mean RSI of patients with LPR after 6 months of PPI therapy approached that of asymptomatic controls (p > 0.05). The RSI is easily administered, highly reproducible, and exhibits excellent construct and criterion-based validity.     

Vocal Improvement After Voice Therapy in Unilateral Vocal Fold Paralysis

Unilateral vocal fold paralysis (UVFP) is associated with changes in acoustic and aerodynamic voice measurements and can have a significant impact on a patient's quality of life. Few objective data regarding the efficacy of voice therapy for UVFP exist. The aim of this study was to retrospectively analyze voice modifications in a group of patients with UVFP before and after voice therapy. Forty patients with UVFP of different etiology were included in the study. Each subject had voice therapy with an experienced speech/language pathologist twice a week; the mean number of sessions was 12.6. A multidimensional assessment protocol was used; it included videoendoscopy, the maximum phonation time (MPT), the GIRBAS scale, spectrograms and a perturbation analysis, and the Voice Handicap Index (VHI). Pre- and posttreatment data were compared by means of the Wilcoxon and Student's t tests. A complete glottal closure was seen in 8 patients before voice therapy and in 14 afterward. Mean MPT increased significantly. In the perceptual assessment, the difference was significant for five out of six parameters. A significant improvement was found on spectrographic analysis; as for perturbation analysis, the differences in jitter, shimmer, and noise-to-harmonic ratio values were significant. VHI values showed a clear and significant improvement. A significant improvement of voice quality and quality of life after voice therapy is an often reached and reasonable goal in patients with UVFP.     

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.     

Acoustical Aspects of Vocal Function Following Radiotherapy for Early T1a Laryngeal Cancer

We evaluated acoustic voice characteristics of 18 male patients undergoing radiotherapy. The subjects were seen for voice assessment preradiotherapy and at 1 month, 3 months, 6 months, and 1 year following radiotherapy. A multidimensional voice analysis computer program (IVANS, Avaaz Innovations, 1998) was employed to evaluate measures of traditional frequency and amplitude perturbation as well as time-based and linear prediction (LP) modeled "noise" parameters of the acoustic output in conjunction with perceptual judgments of overall vocal quality. The results indicate vocal deterioration of vocal function immediately following radiotherapy with gradual and significant improvement in acoustic and perceptual features over 9 to 12 months following the radiation treatment. Measures of glottal noise demonstrated higher sensitivity than frequency-based measures of voice perturbation, and with more consistent, less variable changes in acoustical voice output from the preradiation to the 12 month postradiation periods. Future research evaluating vowel type and acoustic perturbation measures with a larger sample of subjects over a longer time period seems warranted.     

Acid reflux and hoarseness

The aim of this study was to investigate the prevalence of acid reflux in patients complaining of hoarseness where no organic disease or functional dysphonia could be found. We also aimed to determine whether anti-reflux treatment improved their symptoms. Patients were not selected on the basis of symptoms of reflux. Fifty patients with hoarseness took part in a prospective study that sought to establish objectively whether acid reflux was present. All patients were given a 6-week course of ranitidine and Gaviscon. Patients were asked to score their voice quality before and after treatment. Although 72% of patients complained of heartburn more than once a week, only 40% proved to have acid reflux. Although subjective improvement after anti-reflux treatment was found in a larger proportion of those with than without proven reflux, the conclusions that can be drawn are limited as there were no satisfactory objective measurements of voice or controls.     

Voice disorders in patients with suspected laryngo-pharyngeal reflux disease

Many symptoms have been recognized in association with laryngo-pharyngealreflux disease (LPRD), but reports of perceptual voice disorders in this condition have been lacking to date. Forty-nine patients with suspected LPRD were studied for five specific perceptual voice characteristics, and these characteristics were compared to the same characteristics in individuals who had never seen an Otolaryngologist for a voice disorder or throat problem (controls). Sixteen of the suspected LPRD patients also underwent 24-hour pH probe studies. All patients with suspected LPRD had significantly increased abnormal perceptual voice characteristics (musculoskeletal tension, hard glottal attack, glottal fry, restricted tone placement, and hoarseness) compared to the controls. Statistical objective differences between the two groups was demonstrated by the presence of increased shimmer in patients with suspected LPRD compared to controls. The differential diagnosis between functional voice disorders and LPRD may be complex, and perceptual parameters may overlap. Interdisciplinary evaluation is advocated.     

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.     

Acoustic voice analysis in patients with Parkinson''s disease treated with dopaminergic drugs

To quantify several acoustic features of the voice in patients withParkinson's disease (PD), 41 patients and 28 age and sex-matched controls were studied. PD severity was assessed with the Unified PD Rating Scale (UPDRS) and the Hoehn and Yahr staging. The Computerized Speech Lab 4300 program (Kay Elemetrics) was used. Two seconds of a sustained /a/ and a sentence were captured with a microphone and laryngograph equipment. Measures included fundamental frequency (FO), frequency perturbation (fitter), intensity perturbation (shimmer), and harmonic/noise ratio (H/N) of the vowel /a/, and frequency and intensity variability of a sentence, phonational range, dynamic range at the natural frequency, maximum phonational time and s/z ratio. All subjects underwent indirect laryngoscopy and/or laryngeal fibroscopy. When compared with controls, PD patients showed higher jitter, lower H/N ratio, lower frequency and intensity variability of the sentence, and lower phonational range and reported a higher frequency of the presence of low voice-intensity, monopitch, voice arrests, and struggle. These features seem to be unaffected by the duration and severity of the disease.     

The Effects of Frequency Range, Vowel, Dynamic Loudness Level, and Gender on Nasalance in Amateur and Classically Trained Singers

This study addresses two questions: (1) How much nasality is present in classical Western singing? (2) What are the effects of frequency range, vowel, dynamic level, and gender on nasality in amateur and classically trained singers? The Nasometer II 6400 by KayPENTAX (Lincoln Park, NJ) was used to obtain nasalance values from 21 amateur singers and 25 classically trained singers while singing an ascending five-tone scalar passage in low, mid, and high frequency ranges. Each subject sang the scalar passage at both piano and mezzo-forte dynamic loudness levels on each of the five cardinal vowels (/a/, /e/, /i/, /o/, /u/). A repeated mixed-model analysis indicated a significant main effect for the amateur/classically trained distinction, dynamic loudness level, and vowel, but not for frequency range or gender. The amateur singers had significantly higher nasalance scores than classically trained singers in all ranges and on all vowels except /o/. Dynamic loudness level had a significant effect on nasalance for all subject groups except for female majors in the mid- and high-frequency ranges. The vowel, /i/, received significantly higher nasalance than all of the other vowels. Although results of this study show that dynamic loudness level, vowel, and level of training in classical singing have a significant effect on nasality, nasalance scores for most subjects were relatively low. Only six of the subjects, all of whom were amateur singers, had average nasalance scores that could be considered hypernasal (ie, a nasalance average of 22 or above).     

Vocal stability in functional dysphonic versus healthy voices at different times of voice loading

Functional (nonorganic) dysphonia is often characterized by vocal instability. The purpose of the prospective study was to examine whether there is a difference in vocal instability of functional dysphonic voices compared with healthy ones, this means whether electroglottographic perturbation values differ (1) between healthy and dysphonic voices and (2) between two subgroups of the dysphponic voices (hpertonic and hypotonic dysphonic voices). Twenty-three patients with hypertonic functional dysphonia, 9 with hypotonic functional dysphonia and 31 healthy nonsmokers, were each examined electroglottographically before (Ex 1), immediately after (Ex 2), and 1 hour after (Ex 3) voice loading. Perturbations of frequency, amplitude, quasi-open-quotient, and contact-index were calculated from the EGG signal. At all three times of examination, hypertonic dysphonic voices showed higher perturbations than healthy voices, and they had higher perturbations than hypotonic dysphonic voices before and 1 hour after voice loading. Hypotonic dysphonic voices showed higher perturbations than healthy voices only 1 hour after voice loading. Voice loading induced different reactions in dysphonic voices: Some voices showed increased perturbations, and others exhibited normal or even decreased perturbation immediately after voice loading. Examination of electroglottographic-derived perturbations immediately after voice loading seems not to be useful. Differentiation of hypertonic and hypotonic dysphonic voices was possible with an estimated sensitivity of 88.9% and a specificity of 87.0% by using the sum of the amplitude-perturbation and the quasi-open-quotient-perturbation measured before voice loading.     

Effects of stimulation techniques on vocal responses: Implications for assessment and treatment

During voice evaluation and treatment it is customary for clinicians to elicit samples of the vowel /a/ from clients using various elicitation techniques. The purpose of this study was to compare the effects of four commonly used stimulation tasks on the laryngeal mechanism. Eleven female singing students, studying at a university music school, served as subjects for the study. The subjects phonated the vowel /a/ using 4 vocal stimulation techniques: yawn-sigh, gentle onset, focus, and the use of the voiceless fricative. Videoendoscopic and acoustic evaluations of their productions were done. Results show that, in the first 100 ms following the end of the formant transition, these techniques affected voice differently. The fundamental frequency was found to be highest in the yawn-sigh condition, whereas the maximum frequency perturbation was obtained for the voiceless fricative condition. Planned comparisons were made by comparing the data across 2 dimensions: (1) vowels elicited with voiced contexts versus those elicited with voiceless consonantal contexts and (2) vowels elicited with obstruent versus vowels elicited with nonobstruent consonantal contexts. Some changes in acoustic parameters brought about by these stimulation techniques may be explained on the basis of coarticulatory effects of the consonantal context.     

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.     

Relationship among glottal area, static supraglottic compression, and laryngeal function studies in unilateral vocal fold paresis and paralysis

In this study, we evaluated the relationship between laryngeal function measures and glottal gap ratio and normalized measures of supraglottic behaviors in patients with unilateral vocal fold paresis (UVFP). Thirty-one patients were found to have unilateral vocal fold paresis by videoendoscopy and laryngeal electromyography, and 13 controls participated in this study. Patients with UVFP demonstrated significantly larger glottal gap ratios (p = 0.016) than control subjects. The nonparalyzed or contralateral vocal fold was associated with significantly more static false vocal fold compression (p = 0.03) compared with the paralyzed vocal fold or with the controls. Patients with unilateral vocal fold paresis were divided into subgroups: those with normal or abnormal maximum phonation time, flow, or pressure measures. Smaller glottal gap ratios were identified in patients with normal maximum phonation times and flow measures. Greater false vocal fold activity was identified in unilateral vocal fold paresis patients with normal laryngeal function measures than in unilateral vocal fold paresis patients with abnormal measures. These findings suggest that some patients with documented unilateral paresis and glottal incompetence can compensate for vocal fold weakness such that their acoustic and aerodynamic measures are normal.     

Symptoms of Extraesophageal Reflux in a Community-Dwelling Sample

OBJECTIVES: Extraesophageal reflux disease (EERD) is linked with serious and varied health concerns. The authors' goal was to determine the prevalence of EERD and the effect on health-related quality of life in adults within a large community-based sample. STUDY DESIGN: Survey study conducted in a community setting. METHODS: In the Madison, Wisconsin area, 1845 adult subjects were surveyed. Main outcome measures were frequently of GERD and laryngeal symptoms, the Medical Outcomes Trust Short Form 12 (SF-12), Voice Handicap Index (VHI), and Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaires. RESULTS: More than 66% of subjects reported either GERD or laryngeal symptoms, and 26% reported both GERD and laryngeal symptoms (which reflect symptoms commonly reported for EERD). In addition, 39% of our sample took medicine for heartburn. Forty-four percent of subjects with both GERD and laryngeal symptoms reported occasional breathing difficulties, and 38% of these subjects reported a voice disorder. Significant reductions in perceived quality of general health, digestive health, and voice-related quality of life were found in subjects with both GERD and laryngeal symptoms, in comparison with subjects manifesting each symptom group alone, or in subjects with no symptoms. CONCLUSIONS: The presence of GERD and laryngeal symptoms, and their concurrence, was identified in a substantial number of subjects. The GERD and laryngeal symptoms surveyed represent those most commonly reported for EERD. Because EERD has been linked with tissue damage and reductions in health-related quality of life, it is important to identify these persons and provide treatment before progression of the condition.     

Applying the Voice Handicap Index (VHI) to Dysphonic and Nondysphonic Hebrew Speakers

OBJECTIVE: To evaluate a translated version of the Voice Handicap Index (VHI) as a diagnostic tool for people with and without a laryngeal pathology, among Hebrew speakers. STUDY DESIGN: Parallel group design. METHODS: The VHI was translated and adapted to Hebrew. The translated version was, then, administered to a group of 182 patients with various laryngeal pathologies and a control group of 171 people with no laryngeal pathology. Based on the participants' responses to the VHI, statistical analyses were, initially, performed to assess validity and reliability, and then to evaluate group differences between the pathological and control groups and among the different pathological groups included in the study. RESULTS: Statistical analyses showed high reliability values of the Hebrew version of the VHI (overall Cronbach's alpha r = 0.976). Participants' scores were not affected by their age (P = 0.156) or gender (P = 0.261). The participants in the control group obtained significantly lower scores on the overall VHI score, as well as on all three subscale scores, in comparison with the pathological group (P < 0.001). In addition, within the pathological group, patients with neurogenic pathologies received higher scores than all other pathological groups, whereas patients with laryngeal inflammation received lower scores than all other pathological groups (P < 0.05). CONCLUSION: The VHI is a powerful tool for quantifying patients' perceptions of their voice handicaps, and it maintained its power across translation. The VHI was shown to be valuable for the assessment of speakers with, as well as without laryngeal pathologies.