Severe Voice Disorders Research Articles

Multidimensional Voice Assessment After Management of Early Laryngeal Cancer: A Comparative Study.

Laryngeal Squamous Cell Carcinoma is one of the most common head and neck cancers, and patients experience dysphonia after treatment with transoral laser microsurgery (TLM) or radiotherapy (RT). This study aimed to investigate the multidimensional assessment of voice, based on objective and subjective evaluation. In this cross-sectional study, a group of 120 patients (mean = 57.59years, SD = 4.87), including men (n = 116) and women (n = 4) with early laryngeal carcinoma, were divided into two groups; Patients who had undergone TLM (n = 60) or RT (n = 60). The multidimensional assessment of voice was conducted using the acoustic analysis, the dysphonia severity index (DSI), the Persian versions of Consensus Auditory Perceptual Evaluation of Voice, and the voice handicap index (VHI). Results revealed that objective voice assessment only shows differences (P < 0.001) in the DSI between TLM and RT groups, despite there being no significant differences (P = 0.196) in overall severity of voice disorder in comparison between them. Also, there is a significant difference (P < 0.05) based on the Emotional subscale of VHI, between irradiated and TLM-treated patients. This finding showed that TLM-treated patients with early laryngeal carcinoma had severe voice disorder compared to irradiated patients. In addition, radiotherapy has a greater impact on the emotions of patients with early glottic cancer.

Assessment of Vocal Fold Stiffness by Means of High-Speed Videolaryngoscopy with Laryngotopography in Prediction of Early Glottic Malignancy: Preliminary Report.

Simple SummaryThe method described in our manuscript can help to objectively assess the vibration of each vocal fold using larygotopographic analysis of high-speed videoendoscopy (HSV) recordings. We have developed image processing and analysis procedures to detect vocal fold regions in HSV films and quantitatively analyze their shape and kinematics. We proposed the term Stiffness Asymmetry Index which can provide valuable information on the texture and kinematic properties of individual vocal fold tissues, which can be important in the diagnosis of early glottis cancer. Our study showed that a low value of SAI indicated large, non-vibrating vocal fold areas, characteristic of infiltrative lesions such as invasive carcinoma. This important clinical information can help to assess the depth of vocal fold invasion before direct histologic examination and discriminate benign from malignant lesions.One of the most important challenges in laryngological practice is the early diagnosis of laryngeal cancer. Detection of non-vibrating areas affected by neoplastic lesions of the vocal folds can be crucial in the recognition of early cancerogenous infiltration. Glottal pathologies associated with abnormal vibration patterns of the vocal folds can be detected and quantified using High-speed Videolaryngoscopy (HSV), also in subjects with severe voice disorders, and analyzed with the aid of computer image processing procedures. We present a method that enables the assessment of vocal fold pathologies with the use of HSV. The calculated laryngotopographic (LTG) maps of the vocal folds based on HSV allowed for a detailed characterization of vibration patterns and abnormalities in different regions of the vocal folds. We verified our methods with HSV recordings from 31 subjects with a normophonic voice and benign and malignant vocal fold lesions. We proposed the novel Stiffness Asymmetry Index (SAI) to differentiate between early glottis cancer (SAI = 0.65 ± 0.18) and benign vocal fold masses (SAI = 0.16 ± 0.13). Our results showed that these glottal pathologies might be noninvasively distinguished prior to histopathological examination. However, this needs to be confirmed by further research on larger groups of benign and malignant laryngeal lesions.

Surgical treatment of unilateral laryngeal paralysis by selective reinnervation in thyroid surgery

State of the problem: One of the complications in thyroid surgery is a lesion of RLN which can be bilateral with a violation of respiratory function of the larynx and unilateral, in which the first priority is a violation of vocal function of the larynx. The most effective treatment for paralysis of the larynx is the method of laryngeal reinnervation, which can be non-selective, which is usually used in unilateral laryngeal paralysis and promotes reinnervation of both abductors and laryngeal adductors. Selective reinnervation is selectively focuses on the reinnervation of individual target muscles, so it is more often used in bilateral laryngeal paralysis. But despite this, it was used in unilateral laryngeal paralysis during surgery on the thyroid gland during intentional resection of the anterior branch of RLN with partial invasion of its tumour process. Aim: evaluation of the results of surgical treatment unilateral laryngeal paralysis by the method selective reinnervation in thyroidectomy. Materials and Methods: clinical case results of patient A. 15 years old with papillary thyroid cancer and metastases to regional lymph nodes of the neck (T4aN1M0) with absence disorders of laryngeal motility before surgery were analyzed. Examination of the larynx and voice examination were performed before surgery, 2-3 days and 6,12 months after surgery. Changes of laryngoscopic images and evaluation of the Indicators: maximum pho- nation time, fundamental frequency, noise to harmonic ratio, Jitter (loc), Shimmer (loc), Voice Handicap Index-30 (VHI-30), completed version of Jacobcon B. Results: Considering extralaryngeal bifurcation of the recurrent laryngeal nerve (RLN) and invasion of the tumor into the adductive branch of RLN on the left, its dissection was performed and end-to-end neuroanastomosis was formed, completed is selective laryngeal reinnervation. In the immediate postoperative period, patients complained of voice disorders. Study of voice parameters corresponded to severe voice disorders. Partial resumption of the mobility of the larynx and voice function was after 6 months. The signs of the laryngoscopic picture and the spectral analysis of the voice corresponded to the indicators before the operation after 12 months Сonclusions 1. Primary selective reinnervation of the larynx can be used to treat unilateral laryngeal paralysis under the following conditions: extralaryngeal branching of the recurrent laryngeal nerve (bifurcation), lesion of only one of its branches, which will provide sufficient coaxiality to perform anastomosis "end-to-end" and preservation electrical integrity of another branch. 2. This method allows you to restore the motility of the denervated vocal folds and the main indicators of the voice. 3. Given only one clinical case of treatment of unilateral laryngeal paralysis by selective reinnervation, this technique needs further study and refinement.

Comparison of teachers' voice disorders before and during COVID-19 pandemic.

&lt;b&gt; Aim:&lt;/b&gt; The aim of the study was to analyze the impact of the COVID-19 pandemic and the related change of the teaching mode from stationary to distance learning on the severity of voice-related ailments among teachers. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Materials and methods:&lt;/b&gt; A questionnaire survey of teachers was conducted to assess voice disorders during stationary and remote work using the Vocal Tract Discomfort (VTDs) scale and Numeric Rating Scale (NRS), and the respondents' subjective feelings were assessed. Demographic and environmental factors associated with voice work were examined. Data on sickness absence, which were obtained from the "Health Needs Maps 2020" Ministry of Health's, were also analyzed. Responses were subjected to statistical analysis. A P-value level below 0.05 was considered statistically significant. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Results:&lt;/b&gt; 128 teachers participated in the survey. The overall assessment of voice disorders using VTDs and NRS scales showed no statistically significant differences for complaints between stationary and remote work. Detailed analysis revealed more se-vere voice disorders in teachers working more than 6 months remotely (P = 0.049) and having more than 20 lessons per week (P = 0.012). Subjective assessment confirmed a significantly lower percentage of teachers reporting voice disorders when wor-king remotely compared to stationary (P = 0.043). This resulted in less sickness absence and a 40% decrease in sick leave related to voice disorders in 2020 compared to 2019. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Conclusions:&lt;/b&gt; During the remote learning period of the COVID-19 pandemic, teachers reported lower severity of voice disor-ders and this influenced the reduction of sickness absences. There were no statistically significant differences in voice complaints as assessed by VTDs and NRS scales for both teaching modes. Several factors affecting the severity of vocal tract disorders were identified - the number of class hours per week (&gt;20) for stationary teaching and a long period of remote teaching (&gt;6 months).

Long-term outcomes of basic fibroblast growth factor treatments in patients with vocal fold scarring, aged vocal fold, and sulcus vocalis

ObjectiveFibrotic changes in the vocal fold mucosa have been observed in patients with vocal fold scarring, aged vocal fold, and sulcus vocalis, which often lead to severe voice disorders. Previous research suggests that the basic fibroblast growth factor (b FGF) improves variations in vocal fold properties [1,2]. Although clinical studies on b FGF treatments have been conducted [3,4,5], these studies only demonstrated the efficacy of this drug over a short period. The present study is the first to investigate the long-term efficacy of b FGF treatment. Methodsb FGF injections were performed in six patients from January of 2016 to December of 2017 at our institution. Patient follow-up continued for at least two years after the last injection. Three patients had vocal fold scarring, two had aged vocal fold atrophy, and one patient had sulcus vocalis. Each vocal fold was injected with 10 µg of b FGF four times. Voice and stroboscopic examinations were performed after surgery (at one month, three months, six months, one year, two years). Fundamental frequency, maximum phonation time (MPT), mean flow rate (MFR), amplitude perturbation quotient (APQ), pitch perturbation quotient (PPQ), and noise-to-harmonic ratio (NHR), and voice handicap index-10 (VHI-10) were examined and compared statistically between the pretreatment time and at each posttreatment time point. ResultsThe speaking F0 had an obvious decreasing tendency, with significant differences suggesting the increase in volume in the vocal folds. Aerodynamic parameters also showed small improvements. The most remarkable improvement was observed in the acoustic parameters, indicating that the treatment could improve the vocal fold to make vibrations symmetrically and regularly for a long period. Achievement of symmetry and regularity on vocal fold vibrations suggested the property changes had happened in the vocal folds. Consequently, the score of VHI-10 had improved, indicating high patient satisfaction with this treatment. Conclusionb FGF injections could be a reliable treatment option for diseases that deteriorate the property of vocal fold.

Complaints of patients with functional dysorders of voice production accompained by hypotonic condition of the vocal apparatus

Complaints of patients with functional dysorders of voice production accompained by hypotonic condition of the vocal apparatus

Voice analysis of early glottic carcinoma treated by carbon dioxide laser

Objective:The aim of this study is to investigate the effect of CO2 laser cordectomy on the voice of early glottic carcinoma. Method:A retrospective analysis of 40 patients who underwent CO2 laser treatment early glottis preoperative clinical data of postoperative laryngeal cancer patients, patients with postoperative recurrence rate, survival rate, and the postoperative complications of patients with preoperative and postoperative laryngoscopy, voice disorders index（voice handicap index, VHI） simplified Chinese version（VHI 13） rating scale, affecting the stability sound quality postoperatively in patients with laryngeal cancer were discussed. Result:All patients underwent voice reexamination 8-97 months after surgery, and the survival rate was 100%, no local recurrence and no obvious postoperative complications. Compared with the healthy control group, there were statistically significant differences in the four indicators F0（fundamental frequency）, Jitter（fundamental frequency perturbation）, Shimmer（amplitude perturbation） and MPT（maximum pronunciation time）, suggesting that CO2 laser surgery resulted in significant changes in acoustic parameters. Jitter and Shimmer indexes in the pre involved combined group were statistically significant different from those in the non involved combined group, suggesting that the sound quality of the pre involved combined group was worse in the postoperative stability period. The VHI score indicated that most patients with early glottic cancer were in severe voice disorder before operation and most were in moderate voice disorder after operation. Compared with the healthy control group, the VHI score and total score of the healthy control group were lower in terms of physiology, psychology and emotion. Compared with the healthy control group, the VHI score and physiology of the early glottic laryngeal cancer patients were lower in the early glottic laryngeal cancer patients before and after surgery, and they were statistically significant. Conclusion:CO2 laser surgery for early glottic cancer, the overall survival rate of patients, low recurrence rate, fewer complications, CO2 laser surgery led to significant changes in acoustic parameters, postoperative sound quality and whether the involvement of pre-associated factors; The total score of VHI and physiological score of early glottic carcinoma patients after CO2 laser operation were better than those before operation.

Normative Value of SVHI-10. Systematic Review and Meta-Analysis

The study aimed to determine the normative value of SVHI-10. The study is a systematic review and a meta-analysis. A systematic literature search was performed using PubMed and ScienceDirect to access relevant databases and to locate outcome studies. Eligibility criteria included type of publication, participant characteristics, and report of outcomes. Data analysis was conducted using the meta-analysis method. Six articles were included for the final analysis. The normative values for the SVHI-10 for a group of 528 subjects were 8.38 with confidence levels of 7.43-9.34 (age range 16-83). Based on the results of the meta-analysis the SVHI-10 can be used as a screening tool for a group of singers. In the future, it would be worthwhile to carry out a subordinate analysis to determine the SVHI-10 range for mild voice disorders or severe voice disorders in singing.

The effect of voice disorders on lexical tone variation: Exploratory study in an African language

Purpose: The aim was to determine if the presence of a voice disorder in speakers of Setswana, an African tone language, will negatively impact the accuracy of identification by typical first language judges of words belonging to tonal minimal pairs.Method: A quasi-experimental between-group comparison and individual case studies were conducted. Five participants with different types and degrees of voice disorders and nine control participants produced 10 tonal minimal word pairs. Five judges had to identify which of a pair was produced.Result: The mean scores of the control and experimental speakers as groups differed, but the difference was not statistically significant. Control participants scored between 19.6/20 and 14.2/20 words correctly identified. Individual data revealed that four of the nine control participants attained at least one perfect score across judges and six had mean scores of 18.0/20 and higher. The highest scoring experimental participant, presenting with a mild voice disorder, attained a mean of 18.0/20. The lowest scoring participant, presenting with the most severe dysphonia, had a mean of 12.2/20 words correctly identified.Conclusion: These preliminary results appear to suggest that a severe voice disorder could compromise lexical tone variation and by implication the intelligibility of a message.

Occupational Voice Disorders in Slovakia Today and in the Past

Abstract Introduction: Voice disorders primarily affect workers in professions with increased voice demands, such as teaching personnel in educational system, singers, lecturers, actors or managers. Severe voice disorders often require a permanent change of work position. Methods: Retrospective analysis of a set of patients with occupational voice disorders who were hospitalized at the Clinic of Occupational Medicine and Toxicology, Martin University Hospital (COMaT, MUH) in the years of 2000–2017. Comparison of the data obtained with the National Centre of Medical Information (NCMI) data on the occurrence of occupational voice disorders throughout the Slovak Republic (SR). Comparison with the retrospective analysis of reported occupational voice disorders in the years of 1967-1996. Case report of a patient with an occupational voice disorder. Results: We point to a long-term low incidence of occupational voice disorders. In the years of 2000-2017, 24 cases of occupational voice disorders were reported in Slovakia, of which 20 cases were reported under item 42-1 and 4 cases under item 42-2 in the List of Occupational Diseases. Through the COMaT, MUH 11 cases of occupational voice disorders were reported during these years, of which 9 cases were listed under item 42-1 and 2 cases under item 42-2. From 1967 to 1996 there were 52 occupational voice disorders reported in Slovakia, of which 45 were under item 42-1 and 7 under item 42-2. Conclusions: As there is a tendency to underestimate the voice difficulties among teaching staff, it is necessary to provide better information about the possible consequences, prevention, and treatment of these diseases. All of this should be in the competency of occupational health services.

Disfonías espasmódicas: estudios acústicos

La disfonía espasmódica es un desorden vocal severo caracterizado por una interrupción involuntaria de la fonación, denominada también distonía focal laríngea. En este estudio se presentan los resultados de una investigación sobre las características acústico-vocales de una población de pacientes con disfonías espasmódicas, y la comparación de las mismas con las de un grupo control (sujetos con el diagnóstico otorrinolaringológico de cuerdas vocales móviles, sin daños estructurales en la mucosa glótica, ni alteraciones neurológicas que involucren la dinámica cordal). Se analizó acústicamente la vocal /a/ investigándose: valor de la frecuencia fundamental, desviación estándar, rango diferencial entre frecuencia máxima y mínima, y número de quiebres fonatorios. Se utilizó para estas mediciones el Sistema de análisis acústico Praat (Boersma y Weenink, 2003). En los resultados no se encontraron diferencias significativas entre las medias de la Frecuencia Fundamental entre ambos grupos estudiados. La comparación de los promedios del desvío estándar de la Frecuencia Fundamental arrojó sin embargo diferencias significativas, así como la comparación de los promedios de los rangos entre frecuencia máxima y mínima. Respecto a la variable Quiebres Fonatorios, se calcularon solamente en el grupo de pacientes ya que ninguno de los sujetos del grupo control presentó interrupciones fonatorias en la emisión de la vocal. Cabe concluirse que la desviación estándar, el rango entre el valor máximo y mínimo de frecuencia fundamental y el número de interrupciones durante la emisión de vocal prolongada pueden utilizarse como indicadores de disfonía espasmódica.

Dysphonia secondary to traumatic avulsion of the vocal fold in infants

Airway compromise due to paediatric intubation injuries is well documented; however, intubation injuries may also cause severe voice disorders. We report our experience and review the world literature on the voice effects of traumatic paediatric intubation. We report five cases of children referred to Great Ormond Street Hospital for Children who suffered traumatic avulsion of the vocal fold at the time of, or secondary to, endotracheal intubation. All children had significant dysphonia and underwent specialist voice therapy. The mechanisms of injury, risk factors and management of the condition are discussed. Children suffering traumatic intubation require follow up throughout childhood and beyond puberty as their vocal needs and abilities change. At the time of writing, none of the reported patients had yet undergone reconstructive or medialisation surgery. However, regular specialist voice therapy evaluation is recommended for such patients, with consideration of phonosurgical techniques including injection laryngoplasty or thyroplasty.

Patient Factors Related to Voice Therapy Attendance and Outcomes

Limited information is available concerning factors that may be associated with attendance and outcomes among patients referred for voice therapy. The purpose of this study was to determine whether patient-related factors could be identified which distinguished patients who attended voice therapy and had positive voice change from those who did not. This retrospective study included medical record information for 100 patients seen at a major urban, academic medical center. The attendance/outcomes of voice therapy resulted in patient division into five groups, those who (1) were successfully discharged from therapy, (2) attended a few sessions, had voices that improved to normal or were near normal and then stopped attending therapy, (3) attended many sessions with some voice gain, (4) failed to improve despite attending voice therapy, or (5) failed to attend voice therapy as recommended. Outcomes for groups 1-3 (53% of patients) were considered successful (positive voice change), whereas outcomes for groups 4 and 5 (47% of patients) were considered unsuccessful. A high percentage of patients (44%) essentially did not attend therapy. Patients having successful outcomes were more likely to be female, younger, employed, with fewer laryngeal diagnoses and medical problems, a less severe voice disorder and lower Voice Handicap Index (VHI) scores at the start of therapy. Patients with more complex laryngeal diagnoses, more perceived vocal severity, occupational issues, more health issues, and higher VHI scores at the time of the initial voice evaluation may be at greater risk for failing to attend voice therapy sessions.

Comparison of High-Speed Digital Imaging with Stroboscopy for Laryngeal Imaging of Glottal Disorders

High-speed digital imaging (HSDI), unlike stroboscopy, is a frequency-independent visualization technique that provides detailed biomechanical assessment of vocal physiology due to increased temporal resolution. The purpose of this study was to investigate the clinical value of HSDI compared to that of stroboscopy across 3 disorder groups classified as epithelial, subepithelial, and neurologic disorders. Judgments of vibratory features of vocal fold edge, glottal closure, phase closure, vertical level, vibratory amplitude, mucosal wave, phase symmetry, tissue pliability, and glottal cycle periodicity from 252 participants were performed by 3 experienced raters. The results revealed that 63% of the data set was noninterpretable for assessment of vibratory function on stro. boscopic analysis because of the severity of the voice disorder (100% of participants with severe voice disorders and 64% of participants with moderate voice disorders), whereas HSDI resulted in analysis of 100% of the data. The neuromuscular group (74%) was the most difficult to analyze with stroboscopy, followed by the epithelial (58%) and subepithelial groups (53%), secondary to the severity of hoarseness. Because it is desirable in clinical examination to observe vocal fold vibrations, which cannot be done in cases of severe dysphonia, HSDI may aid in clinical decision-making when patients exhibit values exceeding 0.87% jitter, 4.4% shimmer, and a signal-to-noise ratio of less than 15.4 dB on acoustic analysis. These measures could serve as minimal indications for use of HSDI. The data suggest that HSDI can be viewed as augmentative to stroboscopy, particularly in cases of moderate to severe aperiodicity, in which HSDI may aid clinical decision-making.

Perception of Individuals With Voice Disorders by Monolingual English, Bilingual Cantonese–English, and Bilingual Russian–English Women

The purpose of this study was to examine the attitudes of monolingual English, bilingual Cantonese-English, and bilingual Russian-English speakers toward individuals with voice disorders. In a mixed experimental design, a total of 30 older and 29 younger female listeners from the 3 language groups rated the voices of 10 females, each with a mild, moderate, or severe voice disorder or with no voice disorder. A semantic differential scale was used to rate the speakers on 21 attributes. Results indicate that the perception of individuals became increasingly negative as the severity of the disorder increased. Results also indicate that Cantonese-English bilinguals rated the individuals with severe voice disorders more negatively than did English monolinguals and that the language groups differed in their ratings for the attributes of beautiful, lovable, clean, and young. There was no overall effect of age of listener. The study demonstrates that although the language groups were uniform in ascribing more negative attributes to individuals as severity of the disorder increased, there were also significant differences between the groups. Exploration of these issues provides information useful to clinicians in setting priorities for intervention that take into account individuals' backgrounds as well as clinical factors.

Thyroplasty revisions: frequency and predictive factors

Summary: Thyroplasty is the most commonly performed type of laryngeal framework surgery, and the surgical indications are gradually being expanded. Although many reports have described thyroplasty results and rates of success, no study has attempted to determine predictors of the need for revisions or other secondary surgical procedures. Methods: Retrospective review of 118 primary thyroplasty procedures performed on 96 patients. Secondary surgical procedures were divided into planned second-stage procedures (all fat implantation due to scarring), touchup procedures (primarily fat or collagen injections to close localized glottic gaps), and thyroplasty revisions (for implant extrusion or slippage). Statistical analysis was performed via the chi-squared technique with p<0.05 considered significant. Results: 96 patients underwent thyroplasty, 58 for vocal fold paresis or paralysis and 38 for other indications. Thirty-two (33%) patients underwent secondary surgical procedures, including 4 planned second stage procedures, and 6 patients with progression of their underlying disease. Thirty-two secondary procedures were performed in the other 22 patients. Professional singers were found to be more likely to require touchup or planned second-stage procedures ( p = 0.029). Patients with abnormal preoperative noise-to-harmonic ratios were more likely to undergo secondary surgeries ( p = 0.039). Maximum phonation time was not associated with need for secondary surgery. Implant material did not influence revision rates. Conclusions: Professional singers and those patients with severe voice disorders (as measured by more abnormal noise-to-harmonic ratios) are more likely to undergo secondary surgical procedures. The choice of implant material does not affect need for secondary surgical procedures.

Perceptive and instrumental examination of voice quality in patients with lip-jaw-palate clefts

In Anglo-American literature, prevalences as high as 41% are reported for voice disorders in cleft lip and palate (CLP) patients. Because of considerable variability in the reported findings and because no prevalence data are available for the German-speaking area, a screening study was conducted. 154 patients with CLP were examined. Voice quality was assessed perceptively according to the rbh-system (roughness, breathiness, hoarseness). Suprasegmentals and nasal resonance were also assessed. Using a new computer programme for the apparative analysis of voice quality, data for pitch, intensity and pertubation (jitter and shimmer) were obtained for 4 sustained vowels. Based on perceptual analysis, we found that the prevalence of severe voice disorders in CLP patients was 6.5% which is lower than reported in most other studies. The incidence of voice disorders in CLP patients is numerically only slightly higher than in the normal population. The acoustic measurements confirm the results of perceptual analysis. Since the prevalence of severe voice disorders was low, none of the pertubation quotients differentiated between modal and disordered voices. A weak correlation was found between jitter and the ratings for hoarseness. 1. While it is appropriate to assume a higher potential risk for vocal dysfunction in CLP patients the actual prevalence in the patients examined is numerically only slightly higher than in normals. 2. For patients with voice disorders, apparative diagnostics of voice quality is a useful and practical adjunct to perceptual analysis which helps profiling individual patients and helps the professional to make decisions for therapy.

Analysis of voice changes after thyroplasty using linear predictive coding.

Objective measurement of vocal quality is difficult in patients with severe voice disorders. Improved success has been reported using a modeling technique known as linear predictive coding. This technique uses an inverse filter to estimate a glottic excitation signal. The pitch amplitude is defined as the height of the first peak of the autocorrelation of the glottic excitation signal. In this study linear predictive coding was used to analyze voice disorders in patients with vocal fold immobility. Voice recordings were made in 16 patients undergoing vocal fold medialization and 10 patients who had no surgical procedure between measurements. The voice quality was rated by three speech pathologists. Five acoustic parameters were calculated from the samples. The best agreement with the listeners' perceptual analysis was achieved using the pitch amplitude. Both pitch amplitude and the perceptual ratings of voice quality improved in patients undergoing vocal fold medialization. Therefore the linear model of speech production and inverse filtering are useful in measuring vocal quality in patients with vocal fold immobility.

Recurrent laryngeal nerve histopathology in spastic dysphonia: a preliminary study.

Spastic dysphonia is a severe voice disorder ordinarily described as psychogenic. Organic-neurologic changes secondary to central or peripheral nervous system involvement have also been postulated and led recently to the surgical treatment of spastic dysphonia by unilateral section of the recurrent laryngeal nerve (RLN). This study reports the histologic findings from these resections of the RLN from patients with an average 9.5 years duration of spastic dysphonia. Thirty percent of the RLNs examined demonstrated significant abnormalities as compared to age-matched controls. Although no reactive changes were noted by light microscopy, groups of fibers which did not stain for myelin or axons were found in RLNs from patients with spastic dysphonia. A preliminary ultrastructural study of these areas in one RLN revealed sheets of unmyelinated axons. These findings suggest an organic basis for spastic dysphonia at least in some patients.