1,720,965 research outputs found
Automated Analysis of Electroglottographic Signal in Adductor Spasmodic Dysphonia
Get PDFThe 51st Annual Medical Student Research Forum at UT Southwestern Medical Center (Tuesday, January 22, 2013, 3-6 p.m., D1.602)Each year the Medical Student Research Program awards students for the best oral presentation and the best poster presentation as judged by faculty across campus. This author received an award as one of the best poster presentations at this forum.INTRODUCTION: The human voice can be evaluated by a variety of methods. Electroglottographic (EGG) signal is produced when vocal fold vibrations produce cyclic fluctuation in the electrical impedance across the larynx. The EGG signal thus reflects the degree of contact between the vocal folds during voice production and provides a measure of voice quality based on phonatory physiology. However, the utility of EGG has been limited because existing methods of EGG signal analysis focus on the evaluation of 2-3 parameters in a segment of sustained vowel production, which does not reflect pathologies more apparent in conversational speech. We hypothesize that the EGG signal can capture perceptually relevant information from continuous speech in adductor spasmodic dysphonia (ADSD), an enigmatic speech disorder.
OBJECTIVES: 1. To develop an automated computer algorithm to analyze the EGG signal in continuous dysphonic speech. 2. To identify EGG waveform features that correlate with the perceived quality of vocal strain in ADSD.
METHODS: A computer program was created and refined in MATLAB to display and analyze EGG data via a graphical user interface (GUI). An automated peak-detection algorithm was developed using the differentiated EGG signal and used to perform simultaneous multi-parameter analysis on the EGG signal from normal speech and speech in patients with ADSD. Between-group comparisons were made using two-tailed Student's t test. Also, intrasubject comparison was made between strained and less-strained syllables in ADSD speech.
RESULTS: A program was successfully written to allow the display and automated analysis of EGG data from samples of continuous dysphonic speech. The program was found to generate data with good internal consistency. Application to normal and ADSD subjects showed that the open quotient parameter was able to distinguish between strained and less-strained syllables with statistical significance (p=0.04).
DISCUSSION/CONCLUSION: We have developed a method to analyze EGG signal from samples of continuous dysphonic speech. The numerical and graphical data obtained support the utility of EGG as an objective means to clinically highlight the speech differences between normal subjects and subjects with ADSD. Further testing to establish normative values for the analyzed EGG parameters and their subsequent comparison with patient EGG data is required to affirm their utility for routine clinical voice assessment.Southwestern Medical Foundatio
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Quantifying the Perceptual Quality of Strain: An Electroglottographic Analysis of Continuous Dysphonic Speech
Get PDFINTRODUCTION: Excessive vocal effort perceived as strain may involve increased vocal fold compression. Electroglottography (EGG) in principle could provide a measure of strain directly connected to oscillatory kinematics at the sound source. The utility of EGG has been limited by considerable inter- and intra-subject variability.
OBJECTIVE: This work aims to (1) develop an algorithm to analyze EGG signal in continuous, dysphonic speech and (2) identify parameters that correlate with strain.
METHODS: EGG signal from 8 normal speakers and 8 subjects with adductor spasmodic dysphonia (ADSD) reading two-sentence excerpts from the Rainbow Passage was processed by the new software developed in MATLAB. The contact quotient (CQ), pulse width at the 50% amplitude level (EGGW50), and various closing slope and opening slope measures were extracted from selected speech segments. Intra-subject and inter-subject comparisons were then made.
RESULTS: None of the EGG parameters differed between normal and ADSD speakers. Within- subject comparison among ADSD speakers showed that the opening slope measure SO7525 distinguished between the strained and unstrained syllables.
CONCLUSION: These results provide further insight into the utility and limitations of EGG. While EGG may have limited utility in inter-subject comparison, it may provide a useful objective measure of vocal strain in the same subject with variable degrees of strain or over time
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Clinical Applications of a Computational Voice Simulator
Get PDFThe 54th Annual Medical Student Research Forum at UT Southwestern Medical Center (Monday, January 19, 2016, 2-5 p.m., D1.700)BACKGROUND: Given input vocal fold tissue geometries and mechanical properties, a simulator can produce a virtual voice of a defined pitch and sound pressure level. A simulator gives us a tool to systematically investigate the effects of changes to vocal fold geometry or tissue properties on the voice.
OBJECTIVE:To create a user-friendly graphical interface for the NCVS voice simulator, and to use it to determine gender differences in vocal fold tissue properties.
METHODS: Graphical user interface (GUI): A GUI was programmed in MATLAB, with windows that separately allow user control of (1) vocal fold tissue geometries and mechanical properties, (2) ranges of inputs for "brute force" simulations in which a range of properties are investigated, and (3) optimization parameters that allow "smart" simulations with target pitch and sound pressure levels. Geometric and tissue properties: A literature search was performed to determine reasonable values for vocal fold superficial layer, the vocal ligament, and vocalis muscle to use in the simulator. Gender differences in tissue properties: Two groups of simulations were carried out, one using typical female geometries with the average female speaking voice frequency of 200 Hz, the other using typical male geometries and 100 Hz as the desired target. Assessment of outcome: Each group of simulations comprised of several thousand simulations, with each simulation corresponding to a specific combination of frequency, sound pressure level, and corresponding tissue properties that generated those specific voice qualities. Clusters of solutions were identified with cluster analysis.
RESULTS: Solutions visualized in 2D plots showing a strong linear dependence of voice frequency on the longitudinal shear modulus of the vocal ligament, consistent with the general understanding of vocal physiology. There was no clear dependence of frequency on the other tissue properties. Cluster analysis for the male simulation showed two groups of solutions. The first group had the superficial layer longitudinal shear moduli (μ'1) roughly equal to that of the muscle (μ'3). The second group had a ratio of μ'1/μ'3 between 10-20. This indicates that, for a male voice output of 100 Hz, tissue parameters are most optimal if the superficial layer and muscle have similar stiffness, or if the superficial layer is about 10-20 times stiffer than the muscle. The translayer ratio of μ'2/μ'3 also showed two main clusters: one close to 1 and another at a ratio of around 100. This indicated that, for an average male voice, the vocal ligament and muscle should have comparable stiffness, or the ligament is about 100 times stiffer than the muscle. On the other hand, cluster analysis for the female simulation only showed one solution group, with both μ'1/μ'3 and μ'2/μ'3 ratios of around 1. This indicated that, for a female voice output around 100 Hz, the superficial layer, muscle, and ligament layers all should have comparable stiffness levels.
CONCLUSIONS: We have shown that simulations for female geometric parameters calculate different clusters than those for male parameters, given the same target pitch and SPL. By creating a GUI for the NCVS voice simulator, we are now enabling clinician users explore how various morphological defects and changes can affect the human voice, ultimately leading to improved clinical and surgical outcomes.Southwestern Medical Foundatio
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