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- Parameters for vocal acoustic analysis - cured databasePublication . Fernandes, Joana Filipa Teixeira; Silva, Letícia; Teixeira, Felipe; Guedes, Victor; Santos, Juliana Hermsdorf; Teixeira, João PauloThis paper describes the construction and organization of a database of speech parameters extracted from a speech database. This article intends to inform the community about the existence of this database for future research. The database includes parameters extracted from sounds produced by patients distributed among 19 diseases and control subjects. The set of parameters of this database consists of the jitter, shimmer, Harmonic to Noise Ratio (HNR), Noise to Harmonic Ratio (NHR), autocorrelation and Mel Frequency Cepstral Coefficients (MFCC) extracted from the sound of sustained vowels /a/, /i/ and /u/ at the high, low and normal tones, and a short German sentence. The cured database has a total number of 707 pathological subjects (distributed by the various diseases) and 194 control subjects, in a total of 901 subjects.
- Acoustic analysis of chronic laryngitis - statistical analysis of sustained speech parametersPublication . Teixeira, João Paulo; Fernandes, Joana Filipa Teixeira; Teixeira, Felipe; Fernandes, Paula OdeteThis paper describes the statistical analysis of a set of features extracted from the speech of sustained vowels of patients with chronic laryngitis and control subjects. The idea is to identify which features can be useful in a classification intelligent system to discriminate between pathologic and healthy voices. The set of features analysed consist in the Jitter, Shimmer Harmonic to Noise Ratio (HNR), Noise to Harmonic Ratio (NHR) and Autocorrelation extracted from the sound of a sustained vowels /a/, /i/ and /u/ in a low, neutral and high tones. The results showed that besides the absolute Jitter, no statistical significance exist between male and female voices, considering the classification between pathologic or healthy. Any of the analysed parameters is likely to be a statistical difference between control and Chronic Laryngitis groups. This is an important information that these features can be used in an intelligent system to classify healthy from Chronic Laryngitis voices.
- Harmonic to noise ratio measurement - selection of window and lengthPublication . Fernandes, Joana Filipa Teixeira; Teixeira, Felipe; Guedes, Victor; Candido Junior, Arnaldo; Teixeira, João PauloHarmonic to Noise Ratio (HNR) measures the ratio between periodic and non-periodic components of a speech sound. It has become more and more important in the vocal acoustic analysis to diagnose pathologic voices. The measure of this parameter can be done with Praat software that is commonly accept by the scientific community has an accurate measure. Anyhow, this measure is dependent with the type of window used and its length. In this paper an analysis of the influence of the window and its length was made. The Hanning, Hamming and Blackman windows and the lengths between 6 and 24 glottal periods were experimented. Speech files of control subjects and pathologic subjects were used. The results showed that the Hanning window with the length of 12 glottal periods gives measures of HNR more close to the Praat measures.
- Transfer learning with audioSet to voice pathologies identification in continuous speechPublication . Guedes, Victor; Teixeira, Felipe; Oliveira, Alessa Anjos de; Fernandes, Joana Filipa Teixeira; Silva, Letícia; Candido Junior, Arnaldo; Teixeira, João PauloThe classification of pathological diseases with the implementation of concepts of Deep Learning has been increasing considerably in recent times. Among the works developed there are good results for the classification in sustained speech with vowels, but few related works for the classification in continuous speech. This work uses the German Saarbrücken Voice Database with the phrase “Guten Morgen, wie geht es Ihnen?” to classify four classes: dysphonia, laryngitis, paralysis of vocal cords and healthy voices. Transfer learning concepts were used with the AudioSet database. Two models were developed based on Long-Short-Term-Memory and Convolutional Network for classification of extracted embeddings and comparison of the best results, using cross-validation. The final results allowed to obtaining 40% of f1-score for the four classes, 66% f1-score for Dysphonia x Healthy, 67% for Laryngitis x healthy and 80% for Paralysis x Healthy.
- Análise do stick de hóquei em patins para futuro reforço estruturalPublication . Fernandes, Joana Filipa Teixeira; Queijo, Luis; Rocha, Joãopatins, daí ter surgido o interesse pelo estudo do remate deste desporto. O objetivo deste estudo foi criar condições para analisar o comportamento do stick durante um remate de hóquei em patins. Para tal, recorreu-se a técnicas videográficas de alta velocidade sendo realizadas filmagens de todo o remate. Estas filmagens foram feitas no Laboratório de Tecnologia Biomédica – ESTIG. Os ensaios experimentais realizados, tiveram por base um mecanismo de testes de stick de hóquei em patins desenvolvido no âmbito deste estudo. Desenvolvido o mecanismo, foi necessário fazer a simulação do mesmo, utilizando- se o programa SolidWorks® Dassault Systems ver.2015/2016 - Simulation, antes de se passar à construção, uma vez que era necessário saber se o material a utilizar – aço de construção AISI 1020, suportaria os esforços mecânicos que lhe seriam aplicados. Feitos os ensaios, foi necessário tratar as imagens para de seguida se poderem apresentar os resultados obtidos. Analisando as imagens obtidas em alta-velocidade, foi possível obter uma melhor perceção do comportamento do stick em função da força que lhe é aplicada. De acordo com os cálculos feitos, é de esperar que, com melhorias no mecanismo, nomeadamente na mola e no rolamento, os resultados sejam mais similares aos descritos na literatura. O remate que o mecanismo proporcionou assemelhou-se ao executado por atletas. Os resultados obtidos nos ensaios podem ser fundamentais para o estudo dos futuros materiais a aplicar nos sticks de hóquei em patins, permitindo o seu reforço estrutural.
- Classification of control/pathologic subjects with support vector machinesPublication . Teixeira, Felipe; Fernandes, Joana Filipa Teixeira; Guedes, Victor; Candido Junior, Arnaldo; Teixeira, João PauloThe diagnosis of pathologies using vocal acoustic analysis has the advantage of been noninvasive and inexpensive technique compared to traditional technique in use. In this work the SVM were experimentally tested to diagnose dysphonia, chronic laryngitis or vocal cords paralysis. Three groups of parameters were experimented. Jitter, shimmer and HNR, MFCCs extracted from a sustained vowels and MFCC extracted from a short sentence. The first group showed their importance in this type of diagnose and the second group showed low discriminative power. The SVM functions and methods were also experimented using the dataset with and without gender separation. The best accuracy was 71% using the jitter, shimmer and HNR parameters without gender separation.
- Optimization of glottal onset peak detection algorithm for accurate Jitter measurementPublication . Fernandes, Joana Filipa Teixeira; Borghi, Pedro Henrique; Freitas, Diamantino Silva; Teixeira, João PauloJitter is an acoustic parameter used as input for intelligent systems for the diagnosis of speech related pathologies. This work has the objective to improve an algorithm that allows to extract vocal parameters, and thus improve the accuracy measurement of absolute jitter parameter. Some signals were analyzed, where signal to signal was compared in order to try to understand why the values are different in some signal between the original algorithm and the reference software. In this way, some problems were found that allowed to adjust the algorithm, and improve the measurement accuracy for those signals. Subsequently, a comparative analysis was performed between the values of the original algorithm, the adjusted algorithm and the Praat software (assumed as reference). By comparing the results, it was concluded that the adjusted algorithm allows the extraction of the absolute jitter with values closer to the reference values for several speech signals. For the analysis, sustained vowels of control and pathological subjects were used.
- Análise de um stick de hóquei em patins em remate para futuro desenvolvimento de soluções de reforço estruturalPublication . Fernandes, Joana Filipa Teixeira; Queijo, Luis; Rocha, JoãoDo ponto de vista da engenharia, existe pouca informação sobre o hóquei em patins [1], daí ter surgido o interesse pelo estudo do remate deste desporto. O objetivo desta investigação foi criar condições para analisar o comportamento do stick durante um remate de hóquei em patins, recorrendo a técnicas videográficas. Através da análise das imagens obtidas em alta-velocidade, foi possivel obter uma melhor perceção do comportamento do stick em função da força que lhe é aplicada.
- Determinação da autocorrelação, HNR e NHR para análise acústica vocalPublication . Fernandes, Joana Filipa Teixeira; Teixeira, João PauloEste trabalho teve como objetivo a determinação dos parâmetros: Harmonic to Noise Ration (HNR), Noise to Harmonic Ratio (NHR) e Autocorrelação. Estes parâmetros são usados como entradas de um sistema inteligente para diagnóstico de patologias da fala. Foi realizada uma análise comparativa entre os valores do algoritmo e do software Praat, de modo a perceber qual a melhor janela e o seu comprimento, em número de períodos glotais. Desta análise resultou a decisão de se usar a janela de hanning com um comprimento correspondente a 6 períodos glotais. Através da comparação dos resultados chegou-se à conclusão que este algoritmo permite extrair os parâmetros HNR, NHR e Autocorrelação com valores suficientemente próximos dos valores de referência. Foi ainda desenvolvido um algoritmo para selecionar apenas a parte do sinal onde ocorre fala, eliminando as zonas de silêncio iniciais e finais, para, posteriormente, se extrair os Mel Frequency Cepstral Coefficientes (MFCCs), os Linear Prediction Coefficientes (LPC) e os Line Spectral Frequency (LSF). Ao longo do trabalho foi possível, embora não fosse o objetivo primordial, complementar uma base de dados curada, iniciada numa investigação anteriormente realizada, adicionando mais parâmetros e mais doenças. Esta base de dados ficou agora com os parâmetros MFCC com 13 coeficientes cepstrais, HNR, NHR, Autocorrelação, jitter absoluto, jitter relativo, shimmer absoluto, shimmer relativo, extraídos de 9 locuções correspondentes a 3 vogais em 3 tons e a uma frase, para sujeitos com 19 patologias, mais os sujeitos de controlo. Esta base de dados curada disponibiliza um conjunto de parâmetros sobre estes sinais de fala para a investigação sobre estas 19 patologias.
- Determination of harmonic parameters in pathological voices-efficient algorithmPublication . Fernandes, Joana Filipa Teixeira; Freitas, Diamantino Silva; Candido Junior, Arnaldo; Teixeira, João PauloFeatured Application The paper describes a low-complexity/efficient algorithm to determine the short-term Autocorrelation, HNR, and NHR in sustained vowel audios, to be used in stand-alone devices with low computational power. These parameters can be used as input features of a smart medical decision support system for speech pathology diagnosis. The harmonic parameters Autocorrelation, Harmonic to Noise Ratio (HNR), and Noise to Harmonic Ratio are related to vocal quality, providing alternative measures of the harmonic energy of a speech signal. They will be used as input resources for an intelligent medical decision support system for the diagnosis of speech pathology. An efficient algorithm is important when implementing it on low-power devices. This article presents an algorithm that determines these parameters by optimizing the window type and length. The method used comparatively analyzes the values of the algorithm, with different combinations of window and size and a reference value. Hamming, Hanning, and Blackman windows with lengths of 3, 6, 12, and 24 glottal cycles and various sampling frequencies were investigated. As a result, we present an efficient algorithm that determines the parameters using the Hanning window with a length of six glottal cycles. The mean difference of Autocorrelation is less than 0.004, and that of HNR is less than 0.42 dB. In conclusion, this algorithm allows extraction of the parameters close to the reference values. In Autocorrelation, there are no significant effects of sampling frequency. However, it should be used cautiously for HNR with lower sampling rates.