Snoring is a highly prevalent disorder affecting 20-40% of adult population. Snoring is also a major indicative of obstructive sleep apnea (OSA). Despite the magnitude of effort, the acoustical properties of snoring in relation to physiological states are not yet known. This thesis explores statistical properties of snoring sounds and their association with OSA. First, an unsupervised technique was developed to automatically extract the snoring sound segments from the lengthy recordings of respiratory sounds. This technique was tested over 5665 snoring sound segments of 30 participants and the detection accuracy of 98.6% was obtained. Second, the relationship between anthropometric parameters of snorers with different degrees of obstruction and their snoring sounds’ statistical characteristics was investigated. Snoring sounds are non-Gaussian in nature; thus second order statistical methods such as power spectral analysis would be inadequate to extract information from snoring sounds. Therefore, higher order statistical features, in addition to the second order ones, were extracted. Third, the variability of snoring sound segments within and between 57 snorers with and without OSA was investigated. It was found that the sound characteristics of non-apneic (when there is no apneic event), hypopneic (when there is hypopnea), and post-apneic (after apnea) snoring events were significantly different. Then, this variability of snoring sounds was used as a signature to discriminate the non-OSA snorers from OSA snorers. The accuracy was found to be 96.4%. Finally, it was observed that some snorers formed distinct clusters of snoring sounds in a multidimensional feature space. Hence, using Polysomnography (PSG) information, the dependency of snoring sounds on body position, sleep stage, and blood oxygen level was investigated. It was found that all the three variables affected snoring sounds. However, body position was found to have the highest effect on the characteristics of snoring sounds. In conclusion, snoring sounds analysis offers valuable information on the upper airway physiological state and pathology. Thus, snoring sound analysis may further find its use in determining the exact state and location of obstruction.

The social environment we live in today is exceptionally informal. In the past the type of language the learners used, as well as their spelling ability, gave an indication of the type of education they had received. In present times, it often occurs that people are judged according to their spelling ability to determine whether the specific person is suitable for a certain career. People only realise the importance of writing and spelling correctly once they have completed their studies and started working (often this is too late).This leads to distress and problem situations in universities and schools because learners cannot read and spell. Because of globalization, young people today regard English as the global language. This opens doors for them and the use of English is becoming easier. The result is that Afrikaans is also becoming more informal and this is expressed in the learners' writing and spelling ability. Learners' spelling therefore is atrocious. Decline in language and spelling usage is the result of little (or no) education in spelling in general and also because learners give so little attention to reading lately. Research indicates that students and learners experience the "no rules" of poor spelling (also due to SMS language) as a freeing experience and they do not realise the seriousness of speaking, writing and reading standard Afrikaans. The youth regard this era we live in as "cool" and they believe that it protects them against the embarrassment of poor spelling. A finger is often pointed at educators because learners can no longer read and spell. Educators complain that learners have a "couldn't care less" attitude towards correct spelling. Learners use a telegram style for writing, and poor spelling increasingly occurs in creative writing. They ruin their writing skills with bad spelling. Learners no longer have a general knowledge of spelling words and in this way their poor spelling skills are further weakened. "Upsetting spelling problems" originate because learners are not made aware of the phonemes of sounds from an early age and educators are ignorant of how to develop these awareness skills in learners. In the light of these statements one would expect that educators would have received the necessary guidance concerning spelling methods and strategies for teaching and educating spelling. However, the opposite is true as indicated in the literature, namely that educators often have to depend on their own experience to develop several aspects, for instance to develop phonemic awareness in learners so as to ensure success in spelling. Educators discuss learners, their own successes, etcetera but they never discuss the methods they use. The young and inexperienced educator must depend on book-knowledge, personal initiatives, trial and error as well as spontaneous methods to teach spelling. In this study, attention is focused on the link between phoneme awareness and the spelling ability of learners, especially in the Foundation Phase. To achieve the aim of this study the spelling ability of a group of Grade 3 learners was studied using various tests over a certain period of time. The results showed that learners who have no or very little phonemic awareness also do not possess the necessary spelling skills. This study indicates the importance of phonemic awareness as determinant for good spelling. Consequently a definite link exists between phonemic awareness and spelling. From the empirical study that was conducted it became very clear that the level of phonemic awareness and spelling achievement is determined by the education process and the involvement of the educator. Valid theoretical principles were discussed to highlight the necessity of this aspect. Language gatekeepers and educators, especially in the Foundation Phase, thus have an enormous task to develop phoneme awareness from an early age in learners so that they can become aware of the importance of correct spelling. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2008.

There has been in the past and still is controversy over the genesis of the third heart sound (S3). Recent studies, strongly suggest that S3 is a manifestation of a sudden intrinsic limitation in the expansion of the left ventricle. The thesis has aimed to explore that hypothesis further using combined echocardiographic and spectral analysis techniques. Spectral analysis was carried out via conventional fast fourier transform methods and the maximum entropy method. The efficacy of these techniques, in relation to clinical and scientific application, was explored further. Briefly discussed was the application of autoregressive-moving average (ARMA) modelling for spectral analysis of S3, in relation to further work. Following is a brief synopsis of the thesis: CHAPTER 1 This gives an historical and general introduction to heart sound analysis. Discussed briefly is the physiology of the heart and heart sounds and the diagnostic implications of S3 analysis. CHAPTER 2 Here is discussed the instrumentation system used and phonocardiographic and echocardiographic data aquisition. Data preprocessing and storage is also covered. CHAPTER 3 In this chapter the application of a FFT method and correlation of resultant spectral parameters with echocardiographic parameters is reported. CHAPTER 4 The theoretical development of the maximum entropy technique (based on published papers and expanded) is discussed here. Numerical experiments with the method and associated problems are also discussed. CHAPTER 5 The MEM is applied to the spectral analysis of S3 and compared with the FFT method. Correlation analysis of MEM derived spectral parameters with echocardiograhic data is performed. CHAPTER 6 Here ARMA modelling and application to further work is discussed. An ARMA model from the maxixum entropy coefficients is derived. The application of this model to the deconvolution of the chest wall transfer function is discussed as an approach for further work. / Thesis (M.Sc.)--School of Mathematical Sciences, 1989.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 25, 2008) Vita. Includes bibliographical references.

Thesis (Ph.D.) --University of Montana, 2008. / Title from author supplied metadata. Description based on contents viewed on May 15, 2009. ETD number: etd-12112008-123204. Author supplied keywords: natural sounds ; recreation ; visitor experiences ; national park policy ; soundscape policy ; soundscape management ; winter visitor experiences ; wildland recreation. Includes bibliographical references.

Thesis (doctoral)--Stockholm University, 1992. / Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Comparative Literature, 2009. / Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 1997. / Vita. Includes bibliographical references.

Nesta dissertação, apresenta-se o projeto e a implementação de um instrumento portátil para captação dos sons respiratórios adventícios de forma não invasiva, a partir das vias aéreas, em animais submetidos a ventilação mecânica e com lavagem previa com solução salina. Descrevem-se os ensaios para avaliação da resposta em frequência e sensibilidade do microfone de eletreto que foi fixado nos tubos de um ventilador mecânico de uma Unidade de Terapia Intensiva – UTI, o comportamento da propagação dos sons nos tubos do aparelho de ventilação mecânica e as características dos circuitos eletrônicos projetados para realizar a adequação e digitalização dos sinais sonoros captados pelos microfones e transferidos para um software de gravação instalado em um computador pessoal. Os testes do sistema eletrônico de captação dos sons foram realizados em três porcos submetidos a ventilação mecânica e com monitoramento em tempo real da quantidade de ar nos pulmões através de um tomógrafo de impedância elétrica. Como resultado das gravações, foi possível identificar ruídos de crepitação, induzidos nos animais através de manobras ventilatórias. Conclui-se que o circuito desenvolvido e a fixação do microfone nos tubos possibilitam a captação dos ruídos de crepitação em animais submetidos a ventilação mecânica, evidenciando a boa propagação dos sons ao longo das vias aéreas do sistema respiratório. Discute-se também a possibilidade de utilizar esse sistema em conjunto com o sistema de tomografia por impedância elétrica para identificar a duração e a extensão das alterações no recrutamento pulmonar durante a ventilação mecânica. / This essay presents the project of a portable equipment to capture adventitious respiratory sounds, inside the airways, in animals submitted at mechanical ventilation. It is described the tests for assessment of frequency response and sensitivity of the microphone that was fixed in the tubes of a mechanical ventilator, the behavior of sound propagation in tubes of the system and the characteristics of electronic circuits designed to acquire sound signals by microphones and transferred them to a recording software installed on a personal computer. Tests with the electronic system were performed in three pigs submitted to mechanical ventilation and monitoring in real time the amount of air into the lungs through electrical impedance tomography. Through the recorded sound, it was possible to identify crackles induced in animals by ventilator maneuvers. It was possible to conclude that the developed circuit and setting the microphone in the tube allows to capture crackle sounds on animals with mechanical ventilation, showing a good sound propagation along the airways of the respiratory system. It is also discussed the possibility of using this system with the Electric Impedance Tomography - EIT - to identify the duration and extent of changes in alveolar recruitment during pulmonary ventilation.

Made available in DSpace on 2015-05-14T12:43:23Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1139068 bytes, checksum: 20e143f0ab74dab475fcf96fe785062f (MD5) Previous issue date: 2009-03-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The current research was made in order to demonstrate that students, whose mother language is Brazilian Portuguese (BP), show similar difficulties in learning American English (AE) as a foreign language (EFL). The aim of this research was to investigate the reading process of American English vowels by Brazilian students from Recife/PE, showing reading errors in pronunciation due to a large amount of interferences from their mother language (BP). In here, it was tried to evaluate how social factors such as, age and schooling of mother language which can interfere in the process of the American English acquisition as a foreign language. It was made a percentage process of errors through charts containing number data as well. Identify relations between the AE vowel system and the BP vowel system and how the reading process of EFL is achieved by BP speakers. The research was held in public schools, private schools and universities. For the instrument, it was used phrases containing the twelve vowel sounds of American English. The reading from the speakers works as the methodology of this dissertation. It is concluded that the schooling process displays a deficiency onto the learning of English as a foreign language (EFL). Teachers must be submitted through different training modes and capacitating process so that they can develop a more productive work. / Esta pesquisa foi realizada com intuito de demonstrar que alunos falantes do português do Brasil como língua materna (LM) apresentam dificuldades no que diz respeito ao aprendizado do inglês americano como língua estrangeira (LE). Obteve-se, como objetivo principal, Investigar a leitura das vogais do inglês americano por alunos brasileiros oriundos de Recife/PE, mostrando desvio de pronúncia devido às várias interferências da LM. Como objetivo específico, procurou-se avaliar a influência de fatores sociais, como idade e tipo de escola no ato de ler: avaliar o papel da língua materna no processo de aquisição da leitura do inglês americano como LE; verificar como ocorreu a aquisição da LE; levantar dados numéricos em percentual de erros através de tabelas contendo estes dados numéricos; identificar a relação entre as vogais da língua inglesa Americana e da Língua Portuguesa do Brasil e como é feita a leitura da LE por falantes do português do Brasil. A leitura aconteceu em escolas públicas, particulares e universidades. Como instrumento foi utilizado frases contendo os doze sons das vogais do inglês americano. A leitura áudio-oral por falantes serviu como método para o texto dissertativo. Conclui-se que o processo de escolarização traz uma deficiência em relação ao aprendizado do inglês como LE. Os professores que a ensinam precisam de reciclagem e capacitação para que possam desempenhar um trabalho de forma mais produtiva.