Metabolic Mechanisms of Vocal Fatigue

Vocal fatigue is among the most debilitating conditions affecting individuals with voice disorders. Impressions about mechanisms potentially underlying vocal fatigue have varied depending on how fatigue is defined, participants studied, and measures made, thereby impacting the selection of treatment strategies that may alleviate the condition. However, little is currently known about actual metabolic mechanisms of vocal fatigue. The current study aimed to address this issue by investigating the hypothesis that neuromuscular inefficiency, cardiovascular recovery deficits, or both, may play a role in fatigue. The approach replicated well-vetted approaches in exercise physiology. Metabolic profiles of subjects with vocal fatigue were assessed using gas exchange measures in comparison to two non-fatigue groups: vocally healthy and cardiovascular trained individuals, recruited based on results from a newly vetted questionnaire, the Vocal Fatigue Index (VFI) and laryngeal examination. Participants read out loud at two different loudness levels for a duration of 5 minutes for each task with periods of rest between tasks. Metabolic cost for and recovery time from reading were same across all groups. Oxygen uptake and recovery kinetics (EPOC), ratings of perceived exertion revealed interesting patterns in individuals with vocal fatigue compared to cardiovascular trained individuals in particular. Specifically, slow oxygen uptake kinetics in the vocal fatigue compared to the cardiovascular trained group pointed to utilization of anaerobic energy source to meet the demands of the reading task in the vocal fatigue group, suggesting neuromuscular inefficiency. In contrast, rapid oxygen uptake kinetics in the cardiovascular trained group pointed to utilization of aerobic energy sources and greater neuromuscular efficiency. Similarly, a greater number of individuals in vocal fatigue and vocally healthy groups showed an increase in oxygen consumption post reading (EPOC) compared to the cardiovascular trained group, indicating possible cardiovascular recovery deficits in the former groups. In addition to uncovering potential mechanisms underlying vocal fatigue, including neuromuscular inefficiency and cardiovascular recovery deficits, results from the present study highlight the potential importance of aerobic training to generate aerobic energy required for vocal task demands for both ease of task performance and recovery from it

SYNTHESIZING DYSARTHRIC SPEECH USING MULTI-SPEAKER TTS FOR DSYARTHRIC SPEECH RECOGNITION

Dysarthria is a motor speech disorder often characterized by reduced speech intelligibility through slow, uncoordinated control of speech production muscles. Automatic Speech recognition (ASR) systems may help dysarthric talkers communicate more effectively. However, robust dysarthria-specific ASR requires a significant amount of training speech is required, which is not readily available for dysarthric talkers. In this dissertation, we investigate dysarthric speech augmentation and synthesis methods. To better understand differences in prosodic and acoustic characteristics of dysarthric spontaneous speech at varying severity levels, a comparative study between typical and dysarthric speech was conducted. These characteristics are important components for dysarthric speech modeling, synthesis, and augmentation. For augmentation, prosodic transformation and time-feature masking have been proposed. For dysarthric speech synthesis, this dissertation has introduced a modified neural multi-talker TTS by adding a dysarthria severity level coefficient and a pause insertion model to synthesize dysarthric speech for varying severity levels. In addition, we have extended this work by using a label propagation technique to create more meaningful control variables such as a continuous Respiration, Laryngeal and Tongue (RLT) parameter, even for datasets that only provide discrete dysarthria severity level information. This approach increases the controllability of the system, so we are able to generate more dysarthric speech with a broader range. To evaluate their effectiveness for synthesis of training data, dysarthria-specific speech recognition was used. Results show that a DNN-HMM model trained on additional synthetic dysarthric speech achieves WER improvement of 12.2% compared to the baseline, and that the addition of the severity level and pause insertion controls decrease WER by 6.5%, showing the effectiveness of adding these parameters. Overall results on the TORGO database demonstrate that using dysarthric synthetic speech to increase the amount of dysarthric-patterned speech for training has a significant impact on the dysarthric ASR systems

Advances in Management of Voice and Swallowing Disorders

Special Issue “Advances in Management of Voice and Swallowing Disorders” is dedicated to innovations in screening and assessment and the effectiveness of interventions in both dysphonia and dysphagia. In contemporary practice, novel techniques have been introduced in diagnostics and rehabilitative interventions (e.g., machine learning, electrical stimulation). Similarly, advancements in methodological approaches to validate measures have been introduced (e.g., item response theory using Rasch analysis), prompting the need to develop new, robust measures for use in clinics and intervention studies. Against this backdrop, this Special Issue focuses on studies aiming to improve early diagnostics of laryngological disorders and its management. This issue also welcomes the submission of studies on diagnostic accuracy and psychometrics performance of existing and newly developed measures. This includes but is not limited to studies investigating screening tools with sound diagnostic accuracy and robust psychometric properties. Furthermore, interventions with high levels of evidence in relation to clinical outcome using robust methodology (e.g., sophisticated meta-analytic approaches) are of great interest. This issue provides an overview of the latest advances in voice and swallowing disorders

INVESTIGATING THE EFFICACY OF VOCAL FUNCTION EXERCISES IN IMPROVING VOCAL FUNCTION IN ADULTS IRRADIATED FOR LARYNGEAL CANCERS: A THREE PART DISSERTATION

Deterioration in voice quality following radiation therapy for the treatment of laryngeal cancers (LC) is well documented in literature. The majority of studies show that these voice problems are long term and in some cases permanent. Deterioration in voice quality, especially over a period of time could lead to significant communication difficulties in daily life or in some cases could even result in loss of profession. Despite the negative effects of radiation therapy on voice quality being well documented, few studies have focused on the efficacy of voice therapy in the irradiated LC population. The purpose of this study was to investigate the efficacy of a well researched, evidence based voice therapy approach, known as Vocal Function Exercises (VFEs) in improving vocal function in patients who have been irradiated for LCs. The present study conducted in three systematic stages with distinct and related study aims. The first involved characterizing the head and neck cancer treatment seeking population at the University of Kentucky (UK). Stage 2 involved characterizing vocal function following irradiation for LC using a multidimensional assessment approach. Stage 3 was a phase 2 clinical trial aimed at treating these deficits in vocal function identified through stage 2 using a systematic evidence based voice therapy approach, Vocal Function Exercises. For the phase 2 clinical trial, the comparison group received vocal hygiene (VH) counseling. Observations from stage 1 showed that majority of patients from the treatment seeking population at UK between a 3 year time period from 2008 to 2010 were diagnosed with laryngeal cancers and were treated with chemoradiation therapy. Stage 2 demonstrated a multidimensional deterioration in vocal function following radiation therapy for laryngeal cancers. Stage 3 demonstrated a significant improvement in vocal function across the primary outcome measure (Voice Handicap Index) as a result of VFE+VH. Improvements were also seen in select parameters across the five domains of voice assessment in the VFE group. No significant improvements were observed in the vocal hygiene group in any parameters in each domain of voice assessment. Our study demonstrated adults irradiated for laryngeal cancers demonstrated a multi-dimensional deterioration of vocal function. These changes were long term since study participants were 2- 7 years post radiation therapy. Implementation of VFE+VH demonstrated a significant improvement in voice related quality of life and select parameters across the five domains of voice assessment. The present study demonstrated promising preliminary evidence for the use of VFE+VH to improve vocal function in patients irradiated for laryngeal cancers

Models and Analysis of Vocal Emissions for Biomedical Applications

The International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA) came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy. This edition celebrates twenty years of uninterrupted and succesfully research in the field of voice analysis

Models and Analysis of Vocal Emissions for Biomedical Applications

The Models and Analysis of Vocal Emissions with Biomedical Applications (MAVEBA) workshop came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy

Models and Analysis of Vocal Emissions for Biomedical Applications

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

The relationships among physiological, acoustical, and perceptual measures of vocal effort

The purpose of this work was to explore the physiological mechanisms of vocal effort, the acoustical manifestation of vocal effort, and the perceptual interpretation of vocal effort by speakers and listeners. The first study evaluated four proposed mechanisms of vocal effort specific to the larynx: intrinsic laryngeal tension, extrinsic laryngeal tension, supraglottal compression, and subglottal pressure. Twenty-six healthy adults produced modulations of vocal effort (mild, moderate, maximal) and rate (slow, typical, fast), followed by self-ratings of vocal effort on a visual analog scale. Ten physiological measures across the four hypothesized mechanisms were captured via high-speed flexible laryngoscopy, surface electromyography, and neck-surface accelerometry. A mixed-effects backward stepwise regression analysis revealed that estimated subglottal pressure, mediolateral supraglottal compression, and a normalized percent activation of extrinsic suprahyoid muscles significantly increased as ratings of vocal effort increased (R2 = .60). The second study had twenty inexperienced listeners rate vocal effort on the speech recordings from the first study (typical, mild, moderate, and maximal effort) via a visual sort-and-rate method. A set of acoustical measures were calculated, including amplitude-, time-, spectral-, and cepstral-based measures. Two separate mixed-effects regression models determined the relationship between the acoustical predictors and speaker and listener ratings. Results indicated that mean sound pressure level, low-to-high spectral ratio, and harmonic-to-noise ratio significantly predicted speaker and listener ratings. Mean fundamental frequency (measured as change in semitones from typical productions) and relative fundamental frequency offset cycle 10 were also significant predictors of listener ratings. The acoustical predictors accounted for 72% and 82% of the variance in speaker and listener ratings, respectively. Speaker and listener ratings were also highly correlated (average r = .86). From these two studies, we determined that vocal effort is a complex physiological process that is mediated by changes in laryngeal configuration and subglottal pressure. The self-perception of vocal effort is related to the acoustical properties underlying these physiological changes. Listeners appear to rely on the same acoustical manifestations as speakers, yet incorporate additional time-based acoustical cues during perceptual judgments. Future work should explore the physiological, acoustical, and perceptual measures identified here in speakers with voice disorders.2019-07-06T00:00:00