Thesis (B.Sc)--University of Hong Kong, 2005. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2005." Also available in print.

This thesis is part of an ongoing larger scale research study started in 2004 at the Naval Postgraduate School (NPS) which aims to develop a speech-driven human-machine interface for the operation of semi-autonomous military robots in noisy operational environments. Earlier work included collecting a small database of isolated word utterances of seven words from 20 adult subjects using an in-ear microphone. The research conducted here develops a speaker-independent isolated word recognizer from these acoustic signals based on a discrete-observation Hidden Markov Model (HMM). The study implements the HMM-based isolated word recognizer in three steps. The first step performs the endpoint detection and speech segmentation by using short-term temporal analysis. The second step includes speech feature extraction using static and dynamic MFCC parameters and vector quantization of continuous-valued speech features. Finally, the last step involves the discrete-observation HMM-based classifier for isolated word recognition. Experimental results show the average classification performance around 92.77%. The most significant result of this study is that the acoustic signals originating from speech organs and collected within the external ear canal via the in-ear microphone can be used for isolated word recognition. The second dataset collected under low signal-to-noise ratio conditions with additive noise results in 79% recognition accuracy in the HMM-based classifier. We also compared the classification results of the data collected within the ear canal and outside the mouth via the same microphone. The second dataset collected under low signal-to-noise ratio conditions with additive noise results in 79% recognition accuracy in the HMM-based classifier. We also compared the classification results of the data collected within the ear canal and outside the mouth via the same microphone. Average classification rates obtained for the data collected outside the mouth shows significant performance degradation (down to 63%), over that observed with the data collected from within the ear canal (down to 86%). The ear canal dampens high frequencies. As a result, the HMM model derived for the data with dampened higher frequencies does not accurately fit the data collected outside the mouth, resulting in degraded recognition performances.

Diss. Umeå : Umeå universitet, 2005.

Thesis (Ph.D.). / Written for the Dept. of BioMedical Engineering. Title from title page of PDF (viewed 2008/02/12). Includes bibliographical references.

Made available in DSpace on 2016-04-28T20:16:28Z (GMT). No. of bitstreams: 1 2009 - Sandra Batista dos Santos.pdf: 939793 bytes, checksum: fad008b3d49abcd0c16da05450ee089f (MD5) Previous issue date: 2009-02-16 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Mycoplasma are the smallest and more fastidious prokaryotes known, being responsible by high economical losses in livestock production. Mycoplasmas has been found frequently in the ear canal of goats. In these cases, are very closely related with mites, Psoroptidae and Raillietidae, that carried and disseminate mycoplasmas among the flocks. In Brazil, studies related mycoplasmas in the ear canal of bovine inexist. Like this, in the Chapter I, were surveyed up data on prevalence of mycoplasmas in the ear canal of bovine and your association with mites Raillietia spp., and identification of the two Raillietia species that occur in bovine of southeast, State Rio de Janeiro. The prevalence of Mycoplasma spp. in the ear canal of bovine was considered high, 80% (48/60). In these animals high prevalence was verified Raillietia spp. 76.7% (46/60). The parasitism by mycoplasmas and mites was verified in 40 animals (74.1%), this association was highly significant (p<0.001). Of the females of identified Raillietia 52.3% (101/193) were R. auris and 47.7% (92/193) were R. flechtmanni. In this study, was proven that mycoplasmas and mites in the ear canal of the bovine are closely related and these habitat occur pottentially patogenic mycoplasmas for cattle herds. In the Chapter 2, Mycoplasma mycoides Cluster (GMM) was diagnosed by PCR-REA and indirect immunoperoxidase (IPI), both, carried out in mycoplasmas isolates of hte ear canal. In this study, 35 strains selected in agreement with their biochemistry and physiologic proprieties, were used. Under IPI the prevalence obtained for GMM was 20.0% (12/60) while by PCR-REA it was 41.7% (25/60). The IPI typing of these isolates resulted in 58.3% (7/12) for M.mycoides mycoides LC and 41.7% (5/12) for M. capricolum. PCR-REA for M. mycoides Cluster was confirmed by the amplicon size of 785bp, compatible with this group. After restriction analysis with AluI in all M. mycoides cluster strains and ear canal samples the fragments size obtained were compatible with this group, and neither fragment of 370bp that is compatible with MmmSC of bovine origen it was visualized. / Mycoplasmas s?o os menores e mais fastidiosos procariotos conhecidos, sendo respons?veis por altas perdas econ?micas relacionadas a produtividade em ruminantes. Micoplasmas tem sido encontrados com frequ?ncia em conduto auditivo de caprinos. Nestes casos, est?o estreitamente relacionados com ?caros Psoroptidae e Raillietidae, que carreiam e disseminam micoplasmas entre os rebanhos. No Brasil, estudos sobre Mycoplasma em conduto auditivo de bovinos inexistem. Assim, no Cap?tulo I, foram levantados dados sobre preval?ncia de micoplasmas presentes no conduto auditivo de bovinos e sua associa??o com ?caros Raillietia spp., al?m da identifica??o das duas esp?cies de Raillietia spp. parasitas de conduto auditivo de bovinos da regi?o sudeste do Estado do Rio de Janeiro. A preval?ncia de Mycoplasma spp. no conduto auditivo de bovinos foi considerada alta, 80% (48/60). A preval?ncia de Raillietia spp. foi de 76,7% (46/60). Em 40 (74,1%) animais verificou-se parasitismo por Raillietia spp. e Mycoplasma spp., esta associa??o foi altamente significativa (p<0,001). Das f?meas de Raillietia identificadas 52,3% (101/193) foram R. auris e 47,7% (92/193) foram R. flechtmanni. comprovou-se que micoplasmas e ?caros do conduto auditivo de bovinos est?o estreitamente relacionados e que neste s?tio de localiza??o est?o presentes Mycoplasmas com alto potencial patog?nico para bovinos. No Cap?tulo II, foi realizada tipifica??o molecular dos isolados de Mycoplasma pertencentes ao Grupo Mycoplasma mycoides (GMM) atrav?s da t?cnica de PCR-REA, sendo estes resultados comparados com os obtidos na t?cnica de imunoperoxidase indireta (IPI). A preval?ncia obtida para o GMM na IPI foi de 20,0% (12/60) enquanto na PCR-REA foi de 41,7% (25/60). Das esp?cies de Mycoplasma tipificadas pela IPI 58,3% (7/12) foram M. mycoides subsp. mycoides LC e 41,7% (5/12) foram M. capricolum. Na PCR-REA, GMM, foi confirmado pela visualiza??o de um amplicon de 785bp, compat?vel com este grupo. Na clivagem do produto da PCR com a enzima de restri??o AluI, os fragmentos obtidos foram compat?veis com cepas padr?o do GMM, e dos isolados de conduto auditivo de bovinos estudados, nenhum fragmento de 370pb compat?vel com MmmSC, biotipo bovino foi encontrado.

Abstract: Several alternative ear-canal measures are similar to absorbance in their requirement for prior determination of a Thévenin-equivalent sound…

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Die Untersuchung des externen Gehörkanals stellt beim Pferd, wie auch bei anderen Tieren, einen Teil der klinischen Untersuchung dar. Bis jetzt konnte die Untersuchung des equinen externen Gehörkanals, wenn überhaupt, nur sehr oberflächlich durch Adspektion und Palpation der Ohrmuschel erfolgen. Das lag unter anderem an der großen Sensibilität des Pferdeohrs und den damit verbundenen Abwehrreaktionen, sowie auch an den fehlenden anatomischen Informationen. Zu den selten beschriebenen Erkrankungen des equinen, externen Gehörkanals zählen: Otitis externa, Polypen, Neoplasien, Chondrosen, Stenosen und Parasitenbefall (Ohrmilben). Die Diagnose solcher Erkrankungen konnte bis jetzt nur durch die endoskopische Untersuchung oder computertomographische Untersuchung des Gehörkanals post mortem oder unter Allgemeinanästhesie gestellt werden. Im ersten Teil der vorliegenden Studie wurden anatomische Präparationen an 15 Kadaverschädeln durchgeführt, um die genaue Innervation des equinen externen Gehörkanals darzustellen. Proben des Trommelfells, des N. auricularis magnus und des N. auricularis internus wurden histologisch aufbereitet. Durch die gewonnenen Informationen konnte eine Anästhesie des Gehörkanals durch lokale Infiltration des N. auricularis internus und N. auricularis magnus entwickelt werden. Im zweiten, klinischen Teil der Studie wurde die Anästhesie, nach ultrasonographischer Untersuchung der Region, an beiden Gehörkanälen von 23 Pferden durchgeführt. Die Lokalanästhesie war bei allen Pferden beidseits erfolgreich. Bei drei Pferden musste auf je einer Seite eine größere Menge Lokalanästhetikum verwendet werden, um eine vollständige Desensibilisierung zu erreichen. Dies waren die einzigen Fälle bei denen eine Komplikation durch die Anästhesie im Sinne einer temporären Facialisparese auftrat. Diese war damit klar auf die größere Menge des Lokalanästhetikums zurückzuführen. Durch die entwickelte Lokalanästhesie konnte die endoskopische Untersuchung des externen Gehörkanals bis hin zum Trommelfell am stehenden, sedierten Pferd möglich gemacht werden. Die Endoskopie wurde mit 2 verschiedenen flexiblen Endoskopen (mit 2 mm und 7 mm Durchmesser) durchgeführt. Im Rahmen der Endoskopie wurden die externen Gehörkanäle hinsichtlich ihrer Schleimhautbeschaffenheit, des Verschmutzungsgrades und auftretender Pathologien beurteilt. Der Verschmutzungsgrad variierte zwischen gering- und hochgradig (I-III). Zu den aufgetretenen Pathologien zählten zelluläre und zeruminale Akkumulationen, eine osteomähnliche Umfangsvermehrung, Granulome, Blutungen und Verengungen des externen Gehörkanals.

Comparisons were made between changes in the audibility of bone-conduction stimuli to differences in the sound pressure present in the external auditory canal when ears were occluded. Fifteen listeners with normal middle ear function were tested using pure tones of 250, 500, and 1000 Hz, delivered via a bone-conduction oscillator placed on the mastoid process and the frontal bone. At all three frequencies, and both sites of stimulation, ear canal sound pressures were greater in the occluded than in the unoccluded conditions. Concurrently, the test signals were detected at lower intensities, although the changes in audibility and external canal sound pressure levels were not unity. The occlusion effect was attenuated slightly when the skull was vibrated from the frontal bone.