Acoustic voice analysis by means of the hoarseness diagram

Performance of the phonatory deviation diagram in monitoring voice quality before and after voice exercise in individuals with Parkinson's Disease

PURPOSE

To assess the performance of the phonatory deviation diagram and its measurements in monitoring voice quality before and after voice exercise in individuals with Parkinson's Disease.

METHODS

Retrospective and documentary study. A sample of 30 subjects was used, 50% male, with a mean age of 62.13 ± 9.05 years. The results of the phonatory deviation diagram were analyzed, in the moments before and after vocal exercise with the pushing technique associated with plosive sounds, considering the area, density, shape and location of the diagram in the quadrants. For comparison purposes, the acoustic parameters of jitter, shimmer, glottal to noise excitation ratio and results of the auditory-perceptual analysis, carried out in previous research, were also considered, in the pre- and post-technical moments.

RESULTS

Despite the fact that there was no difference in the distribution of samples in the diagram, after performing the vocal technique, a change in the displacement of the diagram towards the area of normality was identified in the visual qualitative analysis, and there was an association between the general degree of vocal deviation in the analysis auditory perception and the area of the diagram. There was an improvement in the shimmer values after the vocal technique.

CONCLUSION

The displacement of the phonatory deviation diagram towards the area of normality corroborated the results in relation to the general degree of dysphonia, evaluated by the auditory-perceptual analysis and the shimmer results, after the vocal technique. Thus, the diagram shows good performance in monitoring voice quality of individuals with Parkinson's.

Auditory-Perceptual Judgment of Vocal Resonance in Carnatic Singers by Different Groups of Listeners

AIM

This study was aimed at evaluating the auditory perceptual judgments of vocal resonance by professional singers, speech-language pathologists (SLP) with singing training, and SLPs without singing training.

OBJECTIVES

(a) To examine the auditory-perceptual judgments of the phonation samples of professional singers obtained before and after resonant voice therapy (RVT) by professional singers, SLPs with singing training, and SLPs without singing training. (b) To compare the agreement between the auditory-perceptual judgments of the phonation samples obtained before and after RVT by professional singers, SLPs with singing training, and SLPs without singing training METHOD: Three groups of judges formed the participants of the study: group A (professional singers), group B (SLPs with singing training), and group C (SLPs without singing training). The judges were instructed to evaluate the perceptual vocal resonance in the voice samples of two groups of trained Carnatic classical singers.Among these groups, One group received RVT training, and their voice samples were obtained before and after the training, while the other group acted as a control. An auditory perceptual 3-point rating scale was used to rate the vocal resonance. Descriptive and inferential statistical analyses and inter-rater agreement tests were done to understand the auditory perceptual judgment of vocal resonance by the three groups of judges.

RESULTS

The results of the Wilcoxon signed rank test indicated that the post-training auditory perceptual ratings by group A (│Z│ = 2.66; P = 0.008) and group B (│Z│ = 2.36; P = 0.018) were significantly different from their pre-training perceptual rating scores. The post-training ratings by group C were not statistically different compared to their pre-training scores. Also, good agreement levels were found on the weighted Cohen's Kappa coefficient test performed on the judgments made by groups A and B.

CONCLUSION

The listeners compare the voice samples to their own internal representations of a voice which would exclusively depend on the experiences of the listeners. In that way, the perception of intricate voice features of singers, like vocal resonance, could be challenging for SLPs with no experience in singing. The results of this study propose specific training in auditory perceptual judgments for SLPs to ensure efficient and independent service delivery to elite vocal performers like singers.

The Comparison Between Inhalation and Total Intravenous Anesthesia Effect on Voice With Supraglottic Airway Devices for Short-term Anesthesia

OBJECTIVE

Supraglottic airway devices (SADs) are a good alternative to endotracheal intubation (ETI) in short-term anesthesia applications since they have advantages including easy application, lower cost, enabling spontaneous ventilation. Total intravenous anesthesia (TIVA) and desflurane anesthesia allowing rapid recovery are anesthesia methods to be selected. Inhalation anesthesia by desflurane may cause adverse effects on airway mucosa and vocal cord functions. The aim of the present study was to compare the effect of the chosen anesthesia method on voice in gynecological patients who underwent short-term anesthesia with SADs.

MATERIAL AND METHOD

Seventy four patients whom short-term surgical procedure was planned in the Gynecology and Obstetrics Clinic were randomized into two groups for desflurane anesthesia (group D) and TIVA (group T). Voice recording was performed through larynx examination before anesthesia. Perioperative hemodynamic parameters, airway complications and postoperative airway complications were recorded. Laryngeal examination and voice recording were performed for the second time after 24 hours following the anesthesia procedure. Acoustic voice analysis of the patients was evaluated through the Praat program. The conditions including sore throat, dysphagia, and hoarseness were investigated after the anesthesia. Acoustic and aerodynamic properties of the voice, airway complications and pharyngolaryngeal complaints related to the use of SADs were compared in the patients.

RESULT

There was not any significant difference between the groups for demographic data. The SADs type and size have similar characteristics. No significant difference was detected between Group T and Group D for anesthesia duration (P = 0.964). Both anesthesia methods cause similar effects on pharyngolaryngeal functions and voice. No significant difference was found between Group T and Group D in parameters other than the shimmer value of acoustic analysis. A statistically significant increase was observed in the Shimmer variable of group D (P < 0.05). When group T and group D were compared, there was not any significant difference in terms of airway complications, sore throat, dysphagia, and hoarseness.

CONCLUSION

The TIVA and desflurane anesthesia presented similar clinical effects on voice and pharyngolaryngeal morbidity in the short-term gynecological operations through SADs. The increased shimmer value of acoustic voice analysis in Group D suggests that desflurane anesthesia may cause clinically insignificant deterioration on the voice. Further comprehensive studies are needed in order to demonstrate the effect of anesthetic agents on larynx functions in patients whom SADs is used.

Performance of Different Acoustic Measures to Discriminate Individuals With and Without Voice Disorders

The goal of this study is to compare and combine different acoustic features in discriminating subjects with and without voice disorders. A database of 484 adult patients participated in the research. All subjects recorded a sustained vowel /Ɛ/ and underwent a laryngoscopic examination of the larynx. From the results of the laryngeal examination performed by a physician and the auditory-perceptual judgment performed by a Speech-Language Pathologist, the subjects were allocated to the group with (n = 52) and without (n = 432) voice disorder. Four types of acoustic features were used: traditional measures, cepstral measures, nonlinear measures, and recurrence quantification measures. Recordings comprised the emission of the vowel /ε/. Quadratic discriminant analysis was used as classifier. Individual features in the context of traditional, cepstral, and recurrence quantification measures achieved an acceptable performance of ≥70%. Combination of measures improved the classifier performance. The best classification result (86.43% accuracy) was obtained by combining traditional linear and recurrence quantification measures. Results shown that Traditional, Cepstral, and recurrence quantification measures are promising features that capture meaningful information about voice production, which provides good classification performances. The findings of this study can be used to develop a computational tool for voice disorders diagnosis and monitoring.

Performance of the phonatory deviation diagram in the evaluation of rough and breathy synthesized voices

Introduction

Voice disorders alter the sound signal in several ways, combining several types of vocal emission disturbances and noise. The phonatory deviation diagram is a two-dimensional chart that allows the evaluation of the vocal signal based on the combination of periodicity (jitter, shimmer, and correlation coefficient) and noise (Glottal to Noise Excitation) measurements. The use of synthesized signals, where one has a greater control and knowledge of the production conditions, may allow a better understanding of the physiological and acoustic mechanisms underlying the vocal emission and its main perceptual-auditory correlates regarding the intensity of the deviation and types of vocal quality.

Objective

To analyze the performance of the phonatory deviation diagram in the discrimination of the presence and degree of roughness and breathiness in synthesized voices.

Methods

871 synthesized vocal signals were used corresponding to the vowel /ɛ/. The perceptual-auditory analysis of the degree of roughness and breathiness of the synthesized signals was performed using visual analogue scale. Subsequently, the signals were categorized regarding the presence/absence of these parameters based on the visual analogue scale cutoff values. Acoustic analysis was performed by assessing the distribution of vocal signals according to the phonatory deviation diagram area, quadrant, shape, and density. The equality of proportions and the chi-square tests were performed to compare the variables.

Results

Rough and breathy vocal signals were located predominantly outside the normal range and in the lower right quadrant of the phonatory deviation diagram. Voices with higher degrees of roughness and breathiness were located outside the area of normality in the lower right quadrant and had concentrated density.

Conclusion

The normality area and the phonatory deviation diagram quadrant can discriminate healthy voices from rough and breathy ones. Voices with higher degrees of roughness and breathiness are proportionally located outside the area of normality, in the lower right quadrant and with concentrated density.

Performance of Phonatory Deviation Diagrams in Synthesized Voice Analysis

OBJECTIVE

To analyze the performance of a phonatory deviation diagram (PDD) in discriminating the presence and severity of voice deviation and the predominant voice quality of synthesized voices.

METHOD

A speech-language pathologist performed the auditory-perceptual analysis of the synthesized voice (n = 871). The PDD distribution of voice signals was analyzed according to area, quadrant, shape, and density.

RESULTS

Differences in signal distribution regarding the PDD area and quadrant were detected when differentiating the signals with and without voice deviation and with different predominant voice quality. Differences in signal distribution were found in all PDD parameters as a function of the severity of voice disorder.

CONCLUSION

The PDD area and quadrant can differentiate normal voices from deviant synthesized voices. There are differences in signal distribution in PDD area and quadrant as a function of the severity of voice disorder and the predominant voice quality. However, the PDD area and quadrant do not differentiate the signals as a function of severity of voice disorder and differentiated only the breathy and rough voices from the normal and strained voices. PDD density is able to differentiate only signals with moderate and severe deviation. PDD shape shows differences between signals with different severities of voice deviation.

Acoustic Perturbation Measures Improve with Increasing Vocal Intensity in Individuals With and Without Voice Disorders

OBJECTIVE

In vocally healthy children and adults, speaking voice loudness differences can significantly confound acoustic perturbation measurements. This study examines the effects of voice sound pressure level (SPL) on jitter, shimmer, and harmonics-to-noise ratio (HNR) in adults with voice disorders and a control group with normal vocal status.

STUDY DESIGN

This is a matched case-control study.

METHODS

We assessed 58 adult female voice patients matched according to approximate age and occupation with 58 vocally healthy women. Diagnoses included vocal fold nodules (n = 39, 67.2%), polyps (n = 5, 8.6%), and muscle tension dysphonia (n = 14, 24.1%). All participants sustained the vowel /a/ at soft, comfortable, and loud phonation levels. Acoustic voice SPL, jitter, shimmer, and HNR were computed using Praat. The effects of loudness condition, voice SPL, pathology, differential diagnosis, age, and professional voice use level on acoustic perturbation measures were assessed using linear mixed models and Wilcoxon signed rank tests.

RESULTS

In both patient and normative control groups, increasing voice SPL correlated significantly (P < 0.001) with decreased jitter and shimmer, and increased HNR. Voice pathology and differential diagnosis were not linked to systematically higher jitter and shimmer. HNR levels, however, were statistically higher in the patient group than in the control group at comfortable phonation levels. Professional voice use level had a significant effect (P < 0.05) on jitter, shimmer, and HNR.

CONCLUSIONS

The clinical value of acoustic jitter, shimmer, and HNR may be limited if speaking voice SPL and professional voice use level effects are not controlled for. Future studies are warranted to investigate whether perturbation measures are useful clinical outcome metrics when controlling for these effects.

A Meta-Analysis: Acoustic Measurement of Roughness and Breathiness

PURPOSE

Over the last 5 decades, many acoustic measures have been created to measure roughness and breathiness. The aim of this study is to present a meta-analysis of correlation coefficients (r) between auditory-perceptual judgment of roughness and breathiness and various acoustic measures in both sustained vowels and continuous speech.

METHOD

Scientific literature reporting perceptual-acoustic correlations on roughness and breathiness were sought in 28 databases. Weighted average correlation coefficients (rw) were calculated when multiple r-values were available for a specific acoustic marker. An rw ≥ .60 was the threshold for an acoustic measure to be considered acceptable.

RESULTS

From 103 studies of roughness and 107 studies of breathiness that were investigated, only 33 studies and 34 studies, respectively, met the inclusion criteria of the meta-analysis on sustained vowels. Eighty-six acoustic measures were identified for roughness and 85 acoustic measures for breathiness on sustained vowels, in which 43 and 39 measures, respectively, yielded multiple r-values. Finally, only 14 measures for roughness and 12 measures for breathiness produced rw ≥ .60. On continuous speech, 4 measures for roughness and 21 measures for breathiness were identified, yielding 3 and 6 measures, respectively, with multiple r-values in which only 1 and 2, respectively, had rw ≥ .60.

CONCLUSION

This meta-analysis showed that only a few acoustic parameters were determined as the best estimators for roughness and breathiness.

Collinearity and Sample Coverage Issues in the Objective Measurement of Vocal Quality: The Case of Roughness and Breathiness

PURPOSE

The aim of the study was to address the reported inconsistencies in the relationship between objective acoustic measures and perceptual ratings of vocal quality.

METHOD

This tutorial moves away from the more widely examined problems related to obtaining the perceptual ratings and the acoustic measures and centers in less scrutinized issues regarding the procedure to establish the correspondence. Expressions for the most common measure of association between perceptual and acoustic measures (Pearson's r) are derived using a multiple linear regression model. The particular case where the multiple linear regression involves only roughness and breathiness is discussed to illustrate the issues.

RESULTS

Most problems reported regarding inconsistent findings in the relationship between given acoustic measures and particular perceptual ratings could be linked to sample properties not directly related to the actual relationship. The influential sample properties are the collinearity between the regressors in the multiple linear regression and their relative variances. Recommendations on how to rule out this possible cause of inconsistency are given, varying in scope from data collection, reporting, manipulation, and results interpretation.

CONCLUSIONS

The problems described can be extended to more general cases than the exemplified roughness and breathiness sample's coverage. Ruling out this possible cause of inconsistency would increase the validity of the results reported.

Análise acústica de vozes infantis: contribuições do diagrama de desvio fonatório

Resumo:OBJETIVO:analisar o poder discriminatório do diagrama de desvio fonatório na avaliação do tipo de voz predominante e da intensidade do desvio vocal em crianças.MÉTODOS:coletou-se a vogal /ε/ sustentada de 93 crianças. A intensidade do desvio e a qualidade vocal foram analisadas por meio da escala analógico-visual. Utilizou-se o diagrama para a análise acústica, com avaliação da distribuição dos sinais vocais de acordo com a área, quadrante, forma e densidade. Realizou-se o teste de igualdade de proporções e o teste Qui-quadrado(x2) para comparar as variáveis, e o teste de Correlação de Spearman para correlacionar as medidas acústicas e perceptivo-auditivas.RESULTADOS: houve correlação entre a classificação de quadrantes e a intensidade do desvio vocal para todos os parâmetros analisados. Houve diferença estatisticamente significante entre a proporção de crianças com rugosidade, soprosidade, tensão e instabilidade em relação à área, ao quadrante e à forma. Não houve diferença estatisticamente significante entre a proporção de crianças com e sem desvio da qualidade vocal em relação a todos os parâmetros analisados, ao considerar a distribuição das vozes nos quadrantes.CONCLUSÃO: o diagrama de desvio fonatório foi capaz de diferenciar a qualidade vocal predominante por meio da distribuição nos quadrantes, embora não tenha discriminado as vozes infantis saudáveis e alteradas.

Disfonias orgânicas por neoplasias: análise de diagramas de desvio fonatório

OBJETIVO:comparar dados acústicos obtidos por meio de diagrama de desvio fonatório de vozes de pacientes disfônicos submetidos a laringectomias parciais com vozes de sujeitos de mesma faixa etária, porém sem queixa vocal.MÉTODOS:foram estudadas as vozes de 28 sujeitos sendo 14 sujeitos laringectomizados parciais e 14 sujeitos sem queixa vocal, compondo um grupo controle. Ambos os grupos do sexo masculino com mesma faixa etária e nível de escolaridade.RESULTADOS:as vozes dos laringectomizados parciais 100% distribuíram-se fora do quadrante de normalidade, sendo que 64,3% se localizaram no quadrante superior direito, 100% apresentaram desvios horizontais e 85,7% tiveram desvio vertical de ruído. Do grupo controle 28,5% distribuíram-se dentro do quadrante de normalidade, 71,5% localizaram-se no quadrante inferior direito, 57,2% apresentaram desvio horizontal de irregularidade - em shimmere 7,2% em jitter. Apenas 7,2% apresentou desvio vertical de ruído no grupo controle. Houve significância estatística em relação aos parâmetros de jitter, shimmer e GNE (glottal to noise excitation) e entre a distribuição das vozes nos quadrantes direito superior e inferior do diagrama, na presença de vozes alteradas.CONCLUSÃO:o diagrama permitiu analisar e discriminar vozes alteradas daquelas com disfonia após laringectomia parcial diferenciando-as por meio de seus parâmetros, distribuição, localização e tipo de voz sendo considerado um recurso útil para análise vocal.

Language-independent automatic evaluation of intelligibility of chronically hoarse persons

OBJECTIVE

Automatic intelligibility assessment using automatic speech recognition is usually language specific. In this study, a language-independent approach is proposed. It uses models that are trained with Flemish speech, and it is applied to assess chronically hoarse German speakers. The research questions are here: is it possible to construct suitable acoustic features that generalize to other languages and a speech disorder, and is the generated model for intelligibility also suitable for specific subtypes of that disorder, i.e. functional and organic dysphonia?

PATIENTS AND METHODS

73 German-speaking persons with chronic hoarseness read the text 'Der Nordwind und die Sonne'. Perceptual intelligibility scores were used as ground truth during the training of an automatic model that converts speaker level acoustic measurements into intelligibility scores. Cross-validation is used to assess model performance.

RESULTS

The interrater agreement for all patients (n = 73) and for the functional and organic dysphonia subgroups (n = 45 and n = 24) are r = 0.82, r = 0.83 and r = 0.75, respectively. The automatic assessment based on phonologically based acoustic models revealed correlations between perceptual and automatic intelligibility ratings of r = 0.79 (all patients), r = 0.78 (functional dysphonia) and r = 0.80 (organic dysphonia).

CONCLUSION

The automatic, objective measurement of intelligibility is a valuable instrument in an evidence-based clinical practice.

Severity of voice disorders: integration of perceptual and acoustic data in dysphonic patients

Purpose:To analyze the correlation between acoustic measures and intensity of vocal deviation, and its discriminatory power in detecting the presence of vocal change, classifying the severity of the deviation and differencing the type of predominant voice.Methods:The sample comprised 186 patients with dysphonia. The vocal deviation from the vowel/ε/was evaluated by consensus between three speech language pathologists, using a Visual Analog Scale. We extracted the mean and standard deviation (SD) of the fundamental frequency (F0), jitter, shimmer, and Glottal-to-Noise Excitation Ratio (GNE).Results:Mean F0 was negatively correlated with the degree of roughness and positively with the degree of tension. The F0 SD was positively correlated with the overall, roughness, tension, and instability grades. The jitter and shimmer were positively correlated with all perceptual parameters. Only the GNE distinguished between healthy and dysphonic voices and rated the degree of breathiness. The shimmer separated rough voices from not rough voices. The mean F0 was helpful to determine the degree of phonatory tension and to separate rough voices from breathy and strained voices.Conclusion:There is a correlation between the acoustic and auditory perceptual measures. The shimmer, the GNE, and F0 SD can be used to detect roughness, breathing, and strain, respectively. The GNE and mean F0 are useful to classify the degree of breathiness and strain, respectively. The mean F0 distinguished between rough, breathy, and strained voices, with rough voices more severe compared to the other two.

Voicing quantification is more relevant than period perturbation in substitution voices: an advanced acoustical study

Quality of substitution voicing—i.e., phonation with a voice that is not generated by the vibration of two vocal folds—cannot be adequately evaluated with routinely used software for acoustic voice analysis that is aimed at ‘common’ dysphonias and nearly periodic voice signals. The AMPEX analysis program (Van Immerseel and Martens) has been shown previously to be able to detect periodicity in irregular signals with background noise, and to be suited for running speech. The validity of this analysis program is first tested using realistic synthesized voice signals with known levels of cycle-to-cycle perturbations and additive noise. Second, exhaustive acoustic analysis is performed of the voices of 116 patients surgically treated for advanced laryngeal cancer and recorded in seven European academic centers. All of them read out a short phonetically balanced passage. Patients were divided into six groups according to the oscillating structures they used to phonate. Results show that features related to quantification of voicing enable a distinction between the different groups, while the features reporting F₀-instability fail to do so. Acoustic evaluation of voice quality in substitution voices thus best relies upon voicing quantification.

Do women's voices provide cues of the likelihood of ovulation? The importance of sampling regime

The human voice provides a rich source of information about individual attributes such as body size, developmental stability and emotional state. Moreover, there is evidence that female voice characteristics change across the menstrual cycle. A previous study reported that women speak with higher fundamental frequency (F0) in the high-fertility compared to the low-fertility phase. To gain further insights into the mechanisms underlying this variation in perceived attractiveness and the relationship between vocal quality and the timing of ovulation, we combined hormone measurements and acoustic analyses, to characterize voice changes on a day-to-day basis throughout the menstrual cycle. Voice characteristics were measured from free speech as well as sustained vowels. In addition, we asked men to rate vocal attractiveness from selected samples. The free speech samples revealed marginally significant variation in F0 with an increase prior to and a distinct drop during ovulation. Overall variation throughout the cycle, however, precluded unequivocal identification of the period with the highest conception risk. The analysis of vowel samples revealed a significant increase in degree of unvoiceness and noise-to-harmonic ratio during menstruation, possibly related to an increase in tissue water content. Neither estrogen nor progestogen levels predicted the observed changes in acoustic characteristics. The perceptual experiments revealed a preference by males for voice samples recorded during the pre-ovulatory period compared to other periods in the cycle. While overall we confirm earlier findings in that women speak with a higher and more variable fundamental frequency just prior to ovulation, the present study highlights the importance of taking the full range of variation into account before drawing conclusions about the value of these cues for the detection of ovulation.

[The vocal behavior of telemarketing operators before and after a working day]

PURPOSE

To evaluate the vocal behavior of receptive telemarketing operators in pre- and post-work shift moments, and to relate the results to the variable gender.

METHODS

Participants were 55 telemarketing operators (11 men and 44 women) working in a receptive mode in the city of Maceió (Alagoas, Brazil). A questionnaire was applied before the work shift to initially identify the vocal complaints. After that, vocal samples were recorded, comprising sustained emissions and connected speech produced 10 minutes before and 10 minutes after the workday to be later evaluated. Auditory-perceptual and acoustic analyses of voice were conducted.

RESULTS

Vocal complaints and symptoms reported by the operators after the work shift were: dry throat (64%); neck and cervix pain (33%); hoarseness (31%); voice failure (26%); and vocal fatigue (22%).Telemarketing operators presented reduced maximum phonation time before and after the day of work (p=0.645). Data from the auditory-perceptual assessment of voice were similar in pre- and post-shift moments (p=0.645). No difference was found between moments also on acoustic analysis data (p=0.738).

CONCLUSION

Telemarketing operators have high indexes of vocal symptoms after the work shift, and there are no differences between pre- and post-work shift in auditory-perceptual and acoustic assessments of voice.

Perceptual Assessment of Voice Quality: Past, Present, and Future

Despite many years of research, we still do not know how to measure vocal quality. This paper reviews the history of quality assessment, describes some reasons why current approaches are unlikely to be fruitful, and proposes an alternative approach that addresses the primary difficulties with existing protocols.

A high-speed laryngoscopic investigation of aryepiglottic trilling

Six aryepiglottic trills with varied laryngeal parameters were recorded using high-speed laryngoscopy to investigate the nature of the oscillatory behavior of the upper margin of the epilaryngeal tube. Image analysis techniques were applied to extract data about the patterns of aryepiglottic fold oscillation, with a focus on the oscillatory frequencies of the folds. The acoustic impact of aryepiglottic trilling is also considered, along with possible interactions between the aryepiglottic vibration and vocal fold vibration during the voiced trill. Overall, aryepiglottic trilling is deemed to be correctly labeled as a trill in phonetic terms, while also acting as a means to alter the quality of voicing to be auditorily harsh. In terms of its characterization, aryepiglottic vibration is considerably irregular, but it shows indications of contributing quasi-harmonic excitation of the vocal tract, particularly noticeable under conditions of glottal voicelessness. Aryepiglottic vibrations appear to be largely independent of glottal vibration in terms of oscillatory frequency but can be increased in frequency by increasing overall laryngeal constriction. There is evidence that aryepiglottic vibration induces an alternating vocal fold vibration pattern. It is concluded that aryepiglottic trilling, like ventricular phonation, should be regarded as a complex, if highly irregular, sound source.

Organ function and quality of life after transoral laser microsurgery and adjuvant radiotherapy for locally advanced laryngeal cancer

BACKGROUND AND PURPOSE

Transoral laser microsurgery (TLM) and adjuvant radiotherapy are an established therapy regimen for locally advanced laryngeal cancer at our institution. Aim of the present study was to assess value of quality of life (QoL) data with special regard to organ function under consideration of treatment efficacy in patients with locally advanced laryngeal cancer treated with larynx-preserving TLM and adjuvant radiotherapy.

PATIENTS AND METHODS

From 1994 to 2006, 39 patients (ten UICC stage III, 29 UICC stage IVA/B) with locally advanced laryngeal carcinomas were treated with TLM and adjuvant radiotherapy. Data concerning treatment efficacy, QoL (using the VHI [Voice Handicap Index], the EORTC QLQ-C30 and QLQ-H&N35 questionnaires) and organ function (respiration, deglutition, voice quality) were obtained for ten patients still alive after long-term follow-up. Correlations were determined using the Spearman rank test.

RESULTS

After a median follow-up of 80.8 months, the 5-year overall survival rate was 46.8% and the locoregional control rate 76.5%, respectively. The larynx preservation rate was 89.7% for all patients and 100% for patients still alive after follow-up. Despite some verifiable problems in respiration, speech and swallowing, patients showed a subjectively good QoL.

CONCLUSION

TLM and adjuvant radiotherapy is a curative option for patients with locally advanced laryngeal cancer and an alternative to radical surgery. Even if functional deficits are unavoidable in the treatment of locally advanced laryngeal carcinomas, larynx preservation is associated with a subjectively good QoL.

[Automated postlaryngectomy telephone test]

OBJECTIVE

In this study, an objective version of the postlaryngectomy telephone test (PLTT) for measuring speech intelligibility based on automatic speech recognition is presented.

METHODS

Thirty-one patients with tracheoesophageal substitute voice (25 men and six women, 63.4+/-8.7 years) were evaluated by 11 naïve listeners. The automatic measurement of speech intelligibility was expressed by means of word accuracy and word recognition rates, or the percentage of correctly recognized words from a word sequence. These automatic measures were compared with the subjectively obtained PLTT values.

RESULTS

The average PLTT intelligibility of the 11 naïve listeners was 47%; the automatically obtained word accuracy and word recognition rates were much lower (approximately 0% and 15%, respectively). The correlation between subjective and automatic evaluation, however, reached more than 0.9 in some of the examined cases.

CONCLUSION

Automatic speech recognition provides an efficient, objective measure that is equivalent to the overall PLTT intelligibility value.

Voice quality of psychological origin

Variations in voice quality are essentially related to modifications of the glottal source parameters, such as: F0, jitter, and shimmer. Voice quality is affected by prosody, emotional state, and vocal pathologies. Psychogenic vocal pathology is particularly interesting. In the present case study, the speaker naturally presented a ventricular band voice whereas in a controlled production he was able to use a more normal phonation process. A small corpus was recorded which included sustained vowels and short sentences in both registers. A normal speaker was also recorded in similar tasks. Annotation and extraction of parameters were made using Praat's voice report function. Application of the Hoarseness Diagram to sustained productions situates this case in the pseudo-glottic phonation region. Analysis of several different parameters related to F0, jitter, shimmer, and harmonicity revealed that the speaker with psychogenic voice was capable of controlling certain parameters (e.g. F0 maximum) but was unable to correct others such as shimmer.

Artificial Neural Network-based Classification to Screen for Dysphonia Using Psychoacoustic Scaling of Acoustic Voice Features

SUMMARY

For diagnosis and classification of dysphonia, voice specialists can choose from an array of diagnostic tools like perceptual tests or acoustic voice analysis. These methods have in common that they require a high level of specialized training and experience, and therefore are mostly reserved to specialized centers. We aimed at developing an acoustic voice analysis system that could be used as a screening device to monitor, document, and diagnose voice problems that are also encountered by non-voice specialists, such as anesthesiologists, head and neck surgeons, and general surgeons before surgery of the thyroid gland and the upper thoracic aperture. An acoustical feature extraction paradigm that focused on jitter, shimmer, standard deviation of fundamental frequency, and the glottal-to-noise excitation ratio was used to reanalyse 120 voice samples previously analyzed by Schönweiler et al (A Novel Approach to Acoustical Voice Analysis Using Artificial Neural Networks. JARO. 2000:1;270-282). An improved artificial neural network (ANN) was used for classification. Building on this preliminary work, we modified the mathematical algorithm to further improve classification accuracy. Eighty percent of all voice samples could be classified correctly as either healthy or hoarse (sensitivity: 63.0%; specificity: 93.9%; area under the curve: 0.854). The adaptation of the ANN-voice analysis system for mobile use may facilitate its use and acceptance by non-voice specialists for the discovery and documentation of preexisting voice disorders, and may thereby lead to a timely initiation of further diagnosis and therapy by voice specialists.

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.

Automatic evaluation of prosodic features of tracheoesophageal substitute voice

In comparison with laryngeal voice, substitute voice after laryngectomy is characterized by restricted aero-acoustic properties. Until now, an objective means of prosodic differences between substitute and normal voices does not exist. In a pilot study, we applied an automatic prosody analysis module to 18 speech samples of laryngectomees (age: 64.2 +/- 8.3 years) and 18 recordings of normal speakers of the same age (65.4 +/- 7.6 years). Ninety-five different features per word based upon the speech energy, fundamental frequency F(0) and duration measures on words, pauses and voiced/voiceless sections were measured. These reflect aspects of loudness, pitch and articulation rate. Subjective evaluation of the 18 patients' voices was performed by a panel of five experts on the criteria "noise", "speech effort", "roughness", "intelligibility", "match of breath and sense units" and "overall quality". These ratings were compared to the automatically computed features. Several of them could be identified being twice as high for the laryngectomees compared to the normal speakers, and vice versa. Comparing the evaluation data of the human experts and the automatic rating, correlation coefficients of up to 0.84 were measured. The automatic analysis serves as a good means to objectify and quantify the global speech outcome of laryngectomees. Even better results are expected when both the computation of the features and the comparison method to the human ratings will have been revised and adapted to the special properties of the substitute voices.

Perceptual Identification and Acoustic Measures of the Resonant Voice Based on “Lessac's Y-Buzz”—A Preliminary Study With Actors

This study aimed to verify whether the resonant voice based on Lessac's Y-Buzz can be perceived by listeners as resonant and different from habitual voice and to compare them to determine whether this sound exploration improves the vocal production. Nine newly graduated actors, six men and three women without voice complaints, were the subjects. They received a session of Lessac's Y-Buzz training from the primary investigator. Before training, they were asked to sustain the vowel /i/ at comfortable frequency and habitual loudness. After training, they were requested to sustain the Y-Buzz they had learned at a comfortable frequency and habitual loudness. Three speech-language pathologists (SLP) trained in voice developed an auditory-perceptive analysis. The pre- and posttraining voice samples were randomly spliced together, edited, and presented in pairs to perceptual judges who were asked to identify the most resonant of the pair. The voice samples were also acoustically compared through the Hoarseness Diagram and acoustic measures using the VoxMetria Software (CTS, version 2.0s, Brazil). The Y-Buzz trials were identified as resonant voice in 74% of the comparisons. The acoustic measures showed a statistically significant decrease of irregularity (P = 0.002) and shimmer (P = 0.38). The Hoarseness Diagram demonstrated how the resonant voice moved toward the normality for irregularity and noise components. The results showed that the resonant voice based on the Y-Buzz can be identified as resonant and different from normal voicing in the same subject, and it apparently implies a better vocal production demonstrating a significant decrease of shimmer and irregularity through the Hoarseness Diagram evaluation.

Effects of unilateral vocal cord paralysis on objective voice measures obtained by Praat

Unilateral vocal cord paralysis (VCP) affects the objective properties of voice by diminished neurologic control and degenerative changes in laryngeal tissue. The goal of this study was to compare the acoustic parameters of VCP patients with control volunteers using the software Praat. Acoustic analysis results of 18 unilateral VCP patients were compared with age and sex matched 72 normal adult volunteers. Comparison of acoustic analysis results of male and female VCP patients with their age and sex matched control groups revealed statistically significant difference in jitter, shimmer, and noise-to-harmonics ratio values (P < 0.01) in both groups. There were no differences in mean fundamental frequency and intensity values. We conclude that these differences were in accordance with the results obtained by commercially available voice analysis programs. This study reflects the first results obtained with Praat software in VCP patients. Using the software Praat, is free and easy, that supports the clinician to rely on objective scientific data.

Predicting mutational change in the speaking voice of boys

SUMMARY

The authors investigated whether acoustic speaking voice analyses can be used to predict the beginning of mutation in 21 male members of a professional boys' choir. Over a period of 3 years before mutation, children were examined every 3 months by ear, nose, and throat (ENT) and phoniatric specialists. At the same time, the voice was evaluated acoustically using analysis features of the Goettingen Hoarseness Diagram (GHD). Irregularity component and noise component, jitter, shimmer, mean waveform correlation coefficient, and fundamental frequency were determined from recordings of the speaking voice. Significant changes of acoustic features appeared 7 and 5 months before mutation onset, which indicates that vocal function is already restricted 6 months before mutation onset. This acoustic voice analysis is therefore suitable to support the care of the professional singing voice.

Functional anatomy of the recurrent and superior laryngeal nerve

BACKGROUND AND AIMS

The purpose of this study was to present the current topographic and anatomical knowledge in neurolaryngology, with special regard to laryngeal paralyses as a major complication in thyroid surgery.

PATIENTS AND METHODS

Microscopic anatomical preparation of 22 human hemilarynges was accomplished.

RESULTS

Due to their neuroanatomical courses, the following extralaryngeal nerves may be at risk in thyroid surgery: the external branch of the superior laryngeal nerve, the paralaryngeal part of the vagal nerve, the Ansa Galeni, the trunk of the recurrent laryngeal nerve (RLN) and the delicate branches of the RLN to the posterior cricoarytaenoid muscle. The anterior and posterior branches of the RLN (antRLN and postRLN) are less endangered by thyroid surgery because they are covered by the thyroid cartilage and posterior cricoarytaenoid muscle (PCA), respectively. In contrast, the antRLN is vulnerable if a ventilation tube is dislocated, with cuff-induced pressure to the glottic level.

CONCLUSION

The increased knowledge in neurolaryngology provides the basis for a selective neuromonitoring to lower the risk of laryngeal paralyses after thyroid surgery.

Laser microsurgical bilateral posterior cordectomy for the treatment of bilateral vocal fold paralysis

OBJECTIVES

We performed a prospective study to assess respiratory function and voice quality before and after laser microsurgical bilateral posterior cordectomy performed for chronic airway obstruction in patients with bilateral vocal fold paralysis.

METHODS

In 17 patients a laser microsurgical posterior cordectomy was performed as an immediate bilateral approach. Roughness, breathiness, hoarseness, and dyspnea were evaluated both subjectively (on a scale from 0 to 3) and objectively (body plethysmography, computerized voice analysis: Göttingen Hoarseness Diagram).

RESULTS

After laser surgery, the patients' respiratory function was significantly increased and was sufficient for all activities of daily living. The body plethysmographic measure of airway resistance had superior descriptive power and correlated significantly with the clinical degree of dyspnea (scale 0 to 3). Pretreatment and posttreatment impairment of voice quality was objectively documented with the Göttingen Hoarseness Diagram; the phonatory results measured with it correlated significantly with the subjective clinical evaluation of hoarseness. Aphonia did not occur.

CONCLUSIONS

A bilateral approach for laser microsurgical posterior cordectomy combines excellent airway improvement and satisfactory voice preservation. In bilateral vocal fold paralysis, pretreatment and posttreatment clinical data should be evaluated by objective measures.

[Not all vocal cord failure following thyroid surgery is recurrent paresis due to damage during operation. Statement of the German Interdisciplinary Study Group on Intraoperative Neuromonitoring of Thyroid Surgery concerning recurring paresis due to intubation]

Since the phoniatrician H. Bauer described the first case of recurrent laryngeal nerve palsy most likely caused by intubation some 45 years ago, several case reports have been published. However, systematic analyses regarding the frequency of recurrent laryngeal nerve palsies due to intubation are scarce, and none of them has used the proper methods to demonstrate clearly that such a mechanism exists. Currently available data justify the assumption that not every recurrent laryngeal nerve palsy following thyroid surgery is due to the operation itself and that the damage caused by intubation, however, may only account for a minority of these cases. The differential diagnosis of postoperative recurrent laryngeal nerve palsy requires the use of specific tools which go beyond simple laryngoscopy and include stroboscopy as well as intra- and extralaryngeal electromyography. A partial palsy of recurrent laryngeal nerve due to intubation would be associated with severe dysphonia or aphonia, not with dyspnea because of the typical intermediate position of the paralyzed vocal folds with a normal electromyographic function of the cricothyroid muscle. The use of these methods to identify the nature of postoperative recurrent laryngeal nerve palsy is recommended in cases of regular intraoperative neuromonitoring but postoperatively impaired function of the vocal cords.

The reliability and sensitivity to change of acoustic measures of voice quality

This study aimed to evaluate the reliability and sensitivity to change of three commonly used acoustic parameters as measured by the Multi-Dimensional Voice Programme (MDVP); jitter, shimmer and noise-to-harmonic ratio. A total of 231 subjects' voices were recorded and analysed. The sample comprised 145 dysphonic patients who received intervention (surgery or voice therapy), 36 dysphonic patients who received no intervention, and 50 non-dysphonic (normal) subjects. All voices were recorded and analysed on two occasions (before and after treatment, or test-retest assessment) using a standard procedure. These data were analysed using standard psychometric procedures for assessing reliability and responsiveness. The acoustic analysis measures demonstrated poor to moderate reliability and effect size with respect to their sensitivity to change. Caution should be exercised in the injudicious use of computer-based acoustic analysis systems as an isolated measure of voice outcome in any clinical trial of interventions aimed at improving voice quality.

Objective measures of breathy voice quality obtained using an auditory model

While several acoustic measures have been proposed to quantify listener ratings of breathy voice quality, most have failed to give a consistent and high correlation with perceptual ratings of breathiness. One reason for these limitations is that most acoustic measures do not address the nonlinear processes that occur in the peripheral auditory system during the auditory perceptual process. It was hypothesized that modeling such nonlinear events during signal processing may provide objective parameters that better correspond to perceptual ratings of breathy voice quality. Ten listeners rated 27 voice stimuli using a five-point rating scale. Acoustic measures were determined from these stimuli and were selected based on their history of having a moderate to strong correlation to perceptual ratings of breathiness. The stimuli were also analyzed using an auditory model proposed by Moore, Glasberg, and Baer [J. Audio Eng. Soc. 45(4), 224-239 (1997)], and new measures were calculated from the output of this model. These measures included the partial loudness of the signal and the loudness of the aspiration noise. Measures obtained from the output of the auditory model were found to account for a high amount of variance in the perceptual ratings of breathiness.