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

Parameterization of a computational physical model for glottal flow using inverse filtering and high-speed videoendoscopy

High-speed videoendoscopy, glottal inverse filtering, and physical modeling can be used to obtain complementary information about speech production. In this study, the three methodologies are combined to pursue a better understanding of the relationship between the glottal air flow and glottal area. Simultaneously acquired high-speed video and glottal inverse filtering data from three male and three female speakers were used. Significant correlations were found between the quasi-open and quasi-speed quotients of the glottal area (extracted from the high-speed videos) and glottal flow (estimated using glottal inverse filtering), but only the quasi-open quotient relationship could be represented as a linear model. A simple physical glottal flow model with three different glottal geometries was optimized to match the data. The results indicate that glottal flow skewing can be modeled using an inertial vocal/subglottal tract load and that estimated inertia within the glottis is sensitive to the quality of the data. Parameter optimisation also appears to favour combining the simplest glottal geometry with viscous losses and the more complex glottal geometries with entrance/exit effects in the glottis.Peer reviewe

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 4th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2005, held 29-31 October 2005, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

A new method of temporal phase shifting using principle of stroboscopy for characterizing microstructures

Temporal Phase Shifting Interferometry is the most common method for characterization of surface, profile and displacement properties of micro devices. Common methods of phase shifting require PZT based devices that have inherent errors due to non-linearity. To avoid these errors during phase shifting, a new phase shifting technique is presented in this work. A detailed analysis of the temporal phase shifting technique was performed and an optimized methodology for phase shifting was also established. This technique utilizes the advantage of stroboscopic interferometry to create phase shifted images without requiring any component for phase shifting. The feasibility of the proposed method of phase shifting was demonstrated using the developed Acoustic-Optic Modulated Stroboscopic Interferometer (AOMSI) on simple 1D and 2D micro structures designed specifically for this purpose. The proposed method was used for surface profiling and static characterization of the microstructures. Experiments were performed on microcantilevers in order to extract the curvature of the device due to residual stress on it. The same device was tested under a commercial surface profiler with 1Å resolution and the results were found to be in good agreement with the results from the proposed technique. Static characterization was performed to identify the tip deflection and profile variation of the microcantilever in response to various DC voltages. A capacitor-based cantilever was tested under varied electrostatic loads and the deflection of the cantilever was extracted using the proposed method. The deflection of the cantilever was predicted using a theoretical model based on energy method. Static characterization results from the proposed technique were found to be in good agreement with the predicted results. To extend the applicability of this technique without affecting the spatial resolution for micro devices larger than the field of view of the interferometer, stitching method was proposed and three different stitching configurations were also presented. The same device was tested in full-field of view under the commercial profiler. Good agreement between the result of presented stitching methods and commercial profiler demonstrates the reliability of the presented methods for stitching large structures

Analysis of phonation onsets in vowel production, using information from glottal area and flow estimate

A multichannel dataset comprising high-speed videoendoscopy images, and electroglottography and free-field microphone signals, was used to investigate phonation onsets in vowel production. Use of the multichannel data enabled simultaneous analysis of the two main aspects of phonation, glottal area, extracted from the high-speed videoendoscopy images, and glottal flow, estimated from the microphone signal using glottal inverse filtering. Pulse-wise parameterization of the glottal area and glottal flow indicate that there is no single dominant way to initiate quasi-stable phonation. The trajectories of fundamental frequency and normalized amplitude quotient, extracted from glottal area and estimated flow, may differ markedly during onsets. The location and steepness of the amplitude envelopes of the two signals were observed to be closely related, and quantitative analysis supported the hypothesis that glottal area and flow do not carry essentially different amplitude information during vowel onsets. Linear models were used to predict the phonation onset times from the characteristics of the subsequent steady phonation. The phonation onset time of glottal area was found to have good predictability from a combination of the fundamental frequency and the normalized amplitude quotient of the glottal flow, as well as the gender of the speaker. For the phonation onset time of glottal flow, the best linear model was obtained using the fundamental frequency and the normalized amplitude quotient of the glottal flow as predictors.Peer reviewe

Fitting a biomechanical model of the folds to high-speed video data through bayesian estimation

High-speed video recording of the vocal folds during sustained phonation has become a widespread diagnostic tool, and the development of imaging techniques able to perform automated tracking and analysis of relevant glottal cues, such as folds edge position or glottal area, is an active research field. In this paper, a vocal folds vibration analysis method based on the processing of visual data through a biomechanical model of the layngeal dynamics is proposed. The procedure relies on a Bayesian non-stationary estimation of the biomechanical model parameters and state, to fit the folds edge position extracted from the high-speed video endoscopic data. This finely tuned dynamical model is then used as a state transition model in a Bayesian setting, and it allows to obtain a physiologically motivated estimation of upper and lower vocal folds edge position. Based on model prediction, an hypothesis on the lower fold position can be made even in complete fold occlusion conditions occurring during the end of the closed phase and the beginning of the open phase of the glottal cycle. To demonstrate the suitability of the procedure, the method is assessed on a set of audiovisual recordings featuring high-speed video endoscopic data from healthy subjects producing sustained voiced phonation with different laryngeal settings

Models and analysis of vocal emissions for biomedical applications: 5th International Workshop: December 13-15, 2007, Firenze, Italy

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 Workshop has the sponsorship of: Ente Cassa Risparmio di Firenze, COST Action 2103, Biomedical Signal Processing and Control Journal (Elsevier Eds.), IEEE Biomedical Engineering Soc. Special Issues of International Journals have been, and will be, published, collecting selected papers from the conference

Methods and studies of laryngeal voice quality analysis in speech production

Voice quality, defined by John Laver as the characteristic auditory colouring of a speaker's voice, is a significant feature of speech, and it is used to signal various properties such as emotions, intentions, and mood of the speaker. While voice quality measurement techniques and algorithms have been developed, much work is needed to obtain a comprehensive view of the function and analysis of human voice in the production of different voice qualities. Two major research questions are presented in this thesis: First, how can the most important laryngeal voice quality features be analyzed, and second, how do the voice quality features affect different facets of vocal expression? To answer these questions, five separate studies of the analysis methodology and two studies regarding the voice quality behaviour were published. The methodology articles describe a voice source analysis software package; a comparison of multiple voice source parameters in breathy, normal, and pressed phonation; a method for evaluating inverse filtering algorithms; comparison of two inverse filtering algorithms; and a method for analyzing intensity regulation of speech. One analysis article studies changes in the laryngeal voice quality when different emotions are expressed in speech and another voice quality changes in expression of prominence in continuous speech. The methodology studies resulted in new tools, methods, and guidelines for voice source analysis, while the analysis studies provide information on how voice quality is used in expressive speech