Anne Schützenberger

Voice- and Health-Related Quality of Life in the Elderly

OBJECTIVE Restrictions of verbal communication and high prevalence of voice disorders in the elderly are suspected to influence the quality of life. For assessment, both voice-specific and unspecific methods are already established and fundamental components of clinical diagnostics, but the question of correlation between voice-related and general health-related quality of life is still open in this subpopulation. METHODS One hundred and seven socially active persons aged 65+ years were recruited and asked to complete Voice-Related Quality of Life (V-RQOL) and Short Form (SF)-36 questionnaires. RESULTS There was a mild correlation between V-RQOL score and both of the SF-36 subscores (r(s)=0.28 for the physical subscore and r(s)=0.27 for the mental subscore). CONCLUSION As correlation of voice- and health-related quality of life in elderly persons is only mild, both voice-specific and unspecific assessment methods are required for clinical diagnostics.

Voice Function and Voice-Related Quality of Life in the Elderly

Background: Many studies have referred to the effects of age on voice and the consequences of these changes. However, only little is known about the adverse effects of voice changes on quality of life in the elderly. Objective: This study focuses on self-perception of voice in seniors as assessed by the Voice-Related Quality of Life (V-RQOL) questionnaire, on voice quality as measured by the Dysphonia Severity Index (DSI) and on the correlation between these parameters. Methods: V-RQOL and DSI were measured as previously described in 107 non-treatment-seeking test persons without voice complaints (76 women and 31 men; mean age 78.7 ± 6.8 years, range 66–94 years). Results: The mean V-RQOL value was 94.4 ± 9.8%. The mean value of the DSI in all participants was 1.2 ± 2.4. There was no significant correlation between the V-RQOL and DSI, either in women (p = 0.11), men (p = 0.58) or the whole study group (p = 0.26). Conclusion: Both the V-RQOL questionnaire and the DSI may be applied to seniors. As self-perception of voice and voice function do not correlate, both parameters have to be measured for voice assessment.

Evaluation of Analytical Modeling Functions for the Phonation Onset Process

The human voice originates from oscillations of the vocal folds in the larynx. The duration of the voice onset (VO), called the voice onset time (VOT), is currently under investigation as a clinical indicator for correct laryngeal functionality. Different analytical approaches for computing the VOT based on endoscopic imaging were compared to determine the most reliable method to quantify automatically the transient vocal fold oscillations during VO. Transnasal endoscopic imaging in combination with a high-speed camera (8000 fps) was applied to visualize the phonation onset process. Two different definitions of VO interval were investigated. Six analytical functions were tested that approximate the envelope of the filtered or unfiltered glottal area waveform (GAW) during phonation onset. A total of 126 recordings from nine healthy males and 210 recordings from 15 healthy females were evaluated. Three criteria were analyzed to determine the most appropriate computation approach: (1) reliability of the fit function for a correct approximation of VO; (2) consistency represented by the standard deviation of VOT; and (3) accuracy of the approximation of VO. The results suggest the computation of VOT by a fourth-order polynomial approximation in the interval between 32.2 and 67.8% of the saturation amplitude of the filtered GAW.

Laryngeal High-Speed Videoendoscopy: Sensitivity of Objective Parameters towards Recording Frame Rate

The current use of laryngeal high-speed videoendoscopy in clinic settings involves subjective visual assessment of vocal fold vibratory characteristics. However, objective quantification of vocal fold vibrations for evidence-based diagnosis and therapy is desired, and objective parameters assessing laryngeal dynamics have therefore been suggested. This study investigated the sensitivity of the objective parameters and their dependence on recording frame rate. A total of 300 endoscopic high-speed videos with recording frame rates between 1000 and 15 000 fps were analyzed for a vocally healthy female subject during sustained phonation. Twenty parameters, representing laryngeal dynamics, were computed. Four different parameter characteristics were found: parameters showing no change with increasing frame rate; parameters changing up to a certain frame rate, but then remaining constant; parameters remaining constant within a particular range of recording frame rates; and parameters changing with nearly every frame rate. The results suggest that (1) parameter values are influenced by recording frame rates and different parameters have varying sensitivities to recording frame rate; (2) normative values should be determined based on recording frame rates; and (3) the typically used recording frame rate of 4000 fps seems to be too low to distinguish accurately certain characteristics of the human phonation process in detail.

Effect of the ventricular folds in a synthetic larynx model

Within the human larynx, the ventricular folds serve primarily as a protecting valve during swallowing. They are located directly above the sound-generating vocal folds. During normal phonation, the ventricular folds are passive structures that are not excited to periodical oscillations. However, the impact of the ventricular folds on the phonation process has not yet been finally clarified. An experimental synthetic human larynx model was used to investigate the effect of the ventricular folds on the phonation process. The model includes self-oscillating vocal fold models and allows the comparison of the pressure distribution at multiple locations in the larynx for configurations with and without ventricular folds. The results indicate that the ventricular folds increase the efficiency of the phonation process by reducing the phonation threshold level of the pressure below the vocal folds. Two effects caused by the ventricular folds could be identified as reasons: (1) a decrease in the mean pressure level in the region between vocal and ventricular folds (ventricles) and (2) an increase in the glottal flow resistance. The reason for the first effect is a reduction of the pressure level in the ventricles due to the jet entrainment and the low static pressure in the glottal jet. The second effect results from an increase in the glottal flow resistance that enhances the aerodynamic energy transfer into the vocal folds. This effect reduces the onset threshold of the pressure difference across the glottis.

Robust Automatic Evaluation of Intelligibility in Voice Rehabilitation Using Prosodic Analysis

Speech intelligibility for voice rehabilitation has been successfully evaluated by automatic prosodic analysis. In this paper, the influence of reading errors and the selection of certain words for the computation of prosodic features (nouns only, nouns and verbs, beginning of each sentence, beginnings of sentences and subclauses) are examined. 73 hoarse patients (48.3 ± 16.8 years) read the German version of the text “The North Wind and the Sun”. Their intelligibility was evaluated perceptually by 5 trained experts according to a 5-point scale. Eight prosodic features showed human-machine correlations of r \(\ge \) 0.4. The normalized energy in a word-pause-word interval, computed from all words (r = 0.69 for the full speaker set), the mean of jitter in nouns and verbs (r = 0.67), and the pause duration before a word (r = 0.66) were the most robust features. However, reading errors can significantly influence these results.

Influence of glottal closure on the phonatory process in ex vivo porcine larynges

Many cases of disturbed voice signals can be attributed to incomplete glottal closure, vocal fold oscillation asymmetries, and aperiodicity. Often these phenomena occur simultaneously and interact with each other, making a systematic, isolated investigation challenging. Therefore, ex vivo porcine experiments were performed which enable direct control of glottal configurations. Different pre-phonatory glottal gap sizes, adduction levels, and flow rates were adjusted. The resulting glottal closure types were identified in a post-processing step. Finally, the acoustic quality, aerodynamic parameters, and the characteristics of vocal fold oscillation were analyzed in reference to the glottal closure types. Results show that complete glottal closure stabilizes the phonation process indicated through a reduced left-right phase asymmetry, increased amplitude and time periodicity, and an increase in the acoustic quality. Although asymmetry and periodicity parameter variation covers only a small range of absolute values, these small variations have a remarkable influence on the acoustic quality. Due to the fact that these parameters cannot be influenced directly, the authors suggest that the (surgical) reduction of the glottal gap seems to be a promising method to stabilize the phonatory process, which has to be confirmed in future studies.

Clinical relevance of endoscopic three-dimensional imaging for quantitative assessment of phonation: Clinical Relevance of Endoscopic 3D Imaging

Laser‐based three‐dimensional (3D) imaging allows realistic visualization and absolute measurement of the vocal folds for comprehensive characterization of the oscillation pattern.

Investigation of phonatory characteristics using ex vivo rabbit larynges

Quantitative analysis of phonatory characteristics of rabbits has been widely neglected. However, preliminary studies established the rabbit larynx as a potential model of human phonation. This study reports quantitative data on phonation using ex vivo rabbit larynx models to achieve more insight into dependencies of three main components of the phonation process, including airflow, vocal fold dynamics, and the acoustic output. Sustained phonation was induced in 11 ex vivo rabbit larynges. For 414 phonatory conditions, vocal fold vibrations, acoustic, and aerodynamic parameters were analyzed as functions of longitudinal vocal fold pre-stress, applied air flow, and glottal closure insufficiency. Dimensions of the vocal folds were measured and histological data were analyzed. Glottal closure characteristics improved for increasing longitudinal pre-stress and applied airflow. For the subglottal pressure signal only the cepstral peak prominence showed dependency on glottal closure. In contrast, vibrational, acoustic, and aerodynamic parameters were found to be highly dependent on the degree of glottal closure: The more complete the glottal closure during phonation, the better the aerodynamic and acoustic characteristics. Hence, complete or at least partial glottal closure appears to enhance acoustic signal quality. Finally, results validate the ex vivo rabbit larynx as an effective model for analyzing the phonatory process.

Systematic analysis of fluid-structure-acoustic interactions in an ex-vivo porcine phonation model

Background: The phonation process is a complex interaction of different components, namely, the airflow from the lungs, the mucosal tissue in the larynx, and the resulting acoustic signal. From clinical experience, it is assumed that the presence of a pre-phonatory gap, oscillation asymmetries, and aperiodicities constitute detrimental factors to the resulting voice quality. In order to gain an in-depth understanding of the cause-effect chain and enable effective therapeutic measures, the crucial elements of the process need to be studied in isolation. Materials & Methods: The presented experimental set-up allows a systematic control and monitoring of the individual components of the excised porcine larynx. Varying degrees of asymmetric adduction, pre-phonatory gap size and flow rate reproduce irregular oscillation patterns associated with pathologic voice production. Results: The statistical analysis based on k-means clustering allows the identification of structural and aero-dynamic factors which influence voice quality. In addition to an increase in glottal closure and oscillation symmetry, an increase in glottal flow resistance produced a beneficial effect on the acoustic output signal and the closely coupled subglottal pressure. Conclusion: The clinical applicability and therapeutic value of these insights must be assessed in further studies. Background: The phonation process is a complex interaction of different components, namely, the airflow from the lungs, the mucosal tissue in the larynx, and the resulting acoustic signal. From clinical experience, it is assumed that the presence of a pre-phonatory gap, oscillation asymmetries, and aperiodicities constitute detrimental factors to the resulting voice quality. In order to gain an in-depth understanding of the cause-effect chain and enable effective therapeutic measures, the crucial elements of the process need to be studied in isolation. Materials & Methods: The presented experimental set-up allows a systematic control and monitoring of the individual components of the excised porcine larynx. Varying degrees of asymmetric adduction, pre-phonatory gap size and flow rate reproduce irregular oscillation patterns associated with pathologic voice production. Results: The statistical analysis based on k-means clustering allows the identification of structural and aero-dynamic factors which influe...