203 resultados para MICROPHONE


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Purpose: To analyze the components of the acoustic signal of swallowing using a specific software. Methods: Fourteen healthy subjects ranging in age from 20 to 50 years (mean age 31±10 years), were evaluated. Data collection consisted on the simultaneous capture of the swallowing audio with a microphone and of the swallowing videofluoroscopic image. The bursts of the swallowing acoustic signal were identified and their duration and the interval between them were later analyzed using a specific software, which allowed the simultaneous analyses between the acoustic wave and the videofluoroscopic image. Results: Three burst components were identified in most of the swallows evaluated. The first burst presented mean time of 87.3 milliseconds (ms) for water and 78.2 for the substance. The second burst presented mean time of 112.9 ms for water and 85.5 for the pasty substance. The mean interval between first and second burst was 82.1 ms for water and 95.3 ms for the pasty consistency, and between second and third burst was 339.8 ms for water and 322.0 ms for the pasty consistency. Conclusion: The software allowed the visualization of three bursts during the swallowing of healthy individuals, and showed that the swallowing signal in normal subjects is highly variable.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Engenharia Mecânica - FEG

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A voz e a habilidade vocal são diferentes em cada indivíduo e em cada fase da vida. Devido aos escassos estudos sobre a qualidade vocal de meninos e adolescentes durante a puberdade, o presente estudo teve como objetivo quantificar os seguintes parâmetros da análise acústica da voz: frequência fundamental, jitter, shimmer, relação harmônico-ruído e intensidade. Para entender como se dá a variação da voz com o desenvolvimento de meninos e adolescentes, esses parâmetros foram correlacionados entre si e também com o grau do desenvolvimento puberal de sujeitos do sexo masculino. Métodos: Foram sujeitos desse estudo 110 indivíduos do sexo masculino, com idade entre 11 e 20 anos, estudantes de três escolas estaduais de Macapá, onde foi feita a coleta dos dados. Os sujeitos foram divididos em 4 grupos, 32 sujeitos com idade entre 11 e 12 anos compuseram o Grupo I, 29 sujeitos com idade entre 13 e 15 anos o Grupo II, o Grupo III foi composto por 30 sujeitos com idade entre 16 e 18 anos, e o Grupo IV por sujeitos com idade entre 19 e 20 anos. Todos os sujeitos foram submetidos à gravação da voz diretamente no computador com auxilio de microfone unidirecional. Solicitou-se emissão sustentada da vogal /é/ e fala encadeada: contagem de 1 a 10 e leitura de um parágrafo pré-estabelecido. Em seguida os sujeitos foram avaliados por um médico clínico geral para caracterização do desenvolvimento puberal de acordo com os estágios descritos por Tanner. A análise vocal foi realizada com o programa acústico Voz Metria®. Resultados: Os sujeitos apresentaram F0 média durante a vogal sustentada de 223,28 Hz, 249,86 Hz, 122,63 Hz e 127,61 Hz para os Grupos I, II, III e IV respectivamente. A F0 durante a fala encadeada foi de 217,09 Hz, 246,18 Hz, 117,27 Hz e 123,42 para os Grupos I, II, III e IV respectivamente. Shimmer apresentou valores aumentados nos quatro grupos. Jitter, intensidade e a relação harmônico-ruído mantiveram-se dentro dos padrões de normalidade estabelecidos pelo programa acústico utilizado. Quanto ao desenvolvimento puberal, a maioria dos sujeitos está em G3 (n=38; 34,5%) e G4 (n=42; 38,2%) e P3 (n=34; 31%) e P4 (n=36; 32,7%). O grau de desenvolvimento puberal está correlacionado com aF0 durante a fala encadeada (p<0,001) e com a F0 durante a emissão da vogal sustentada (p<0,001) e essa correlação foi estatisticamente significante entre G2 e G5, e G3 e G5. Conclusão: Até os 15 anos os parâmetros vocais acústicos são típicos da voz infantil. Dos 16 aos 20 anos há decréscimo significativo da F0, porém a voz ainda está em processo de estabilização, com valores aumentados de shimmer. F0 é o único parâmetro correlacionado com o grau de desenvolvimento puberal. A finalização do processo de muda vocal se apresentou, na população estudada, como um evento tardio em relação ao desenvolvimento puberal.

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Pós-graduação em Engenharia Mecânica - FEG

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Neste trabalho se propôs a utilização do MP3 player portátil para gravação de sinal nãoáudio em sua memória, utilizando-se seu recurso para gravação de voz. Para avaliar a proposta, retirou-se o microfone de eletreto do MP3 player e em seu lugar injetou-se um sinal de FM, com portadora de áudio de 1200 Hz modulada pelo sinal de interesse. O sinal é gravado no aparelho em arquivo no formato WAV. Sua recuperação se fez usando um demodulador de FM a PLL cuja entrada é o sinal de FM captado nos terminais da bobina do fone de ouvido do MP3 player. Nos testes, usou-se sinal senoidal e sinal de eletrocardiograma. Embora a qualidade dos sinais de baixa freqüência precise ser melhorada, em geral os resultados apontam para a viabilidade da proposta. Fazem-se sugestões para melhorias e extensões do trabalho.

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In our experiments, we studied the classical dynamic of a particle in vertical motion subject to a constant gravitational field and the partial shock with an elastic wall with oscillatory motion located below the particle. The motion of the particle was confined to the vertical direction by a glass guide tube, which was initially evacuated, allowing viscous drag forces to be disregarded. The time between impacts, as well as the time between the reference phase of the movement of the base and the moment of impact and the period of oscillation of the base will be acquired by a hardware and software to obtain the phases space to be compared later with the description of the system through mapping discrete variables via the 'particle velocity immediately after shock 'and' phase of the movement of the base at the instant of shock 'obtained by computer simulation. This requires developing an electronic analog system followed by Digital implemented in reconfigurable logic, more specifically a sequential machine able to discriminate the impact with the metal base from the impacts of the glass guide tube, based on the frequency spectrum of the response of the microphone to these different impacts

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We present here some results of our research related to the optoelectronics and photonics and show all the experimental setups used. Starting with a discussion on the importance of the waves, we demonstrate our achievements based on employment of acoustic, optical, and microwaves and their technological use. The results concern the acousto-optic and electro-optic effects. The generalized analysis of the electro-optic effect reveals a new high induced birefringence in lithium niobate. A patented optical fiber microphone is presented, and its applications to the measurements of acoustic wave velocity in gases and in the laser ultrasound non-destructive evaluation system are discussed. Finally, the generation of microwaves by an optical method with substantial cost reduction is presented.

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We studied in this work some aspects of the physics of sound and music as a tool for physics teaching. The theory of sound since it is generated by some stimulus to its uptake by the human body, in areas such as: frequency, intensity, tone and propagation. The literature of the subject research was combined with the study of free software that captures waves on a computer, using a microphone, and allows to analyze the waves and frequencies involved in the sound, being able to distinguish tones, frequencies and intensities. We have analyzed some instruments (guitar, harmonica and pitch), including voice, from the quantitative and qualitative point of view. Finally we analyze textbooks in their acoustic topics and try to understand how important these materials give to this topic in basic education. We suggest a teaching sequence that could be applied in a high school classroom

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SHERMAN, D.J.; LI, B.; FERRELL E.J.; ELLIS, J.T.; COX, W.D.; MAIA, L.P., and SOUSA, P.H.G.O., 2011. Measuring Aeolian Saltation: A Comparison of Sensors. In: Roberts, T.M., Rosati, J.D., and Wang, P. (eds.), Proceedings, Symposium to Honor Dr. Nicholas C. Kraus, Journal of Coastal Research, Special Issue, No. 59, pp. 280-290. West Palm Beach (Florida), ISSN 0749-0208. We report the results of field experiments designed to compare four types of aeolian saltation sensors: the Safire; the Wenglor (R) Particle Counter; the Miniphone; and the Buzzer Disc. Sets of sensors were deployed in tight spatial arrays and sampled at rates as fast as 20 kHz. In two of the three trials, the data from the sensors are compared to data obtained from sand traps. The Miniphone and the Buzzer Disc, based on microphone and piezoelectric technologies, respectively, produced grain impact counts comparable to those derived from the trap data. The Satire and the Wenglor (R) Particle Counter produce count rates that were an order of magnitude too slow. Satires undercount because of their large momentum threshold and because its signal is saturated at relatively slow transport rates. We conclude that the Miniphone and the Buzzer Disc are appropriate for deployment as grain counters because their small size allows them to be installed in closely-spaced sets.

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In the context of “testing laboratory” one of the most important aspect to deal with is the measurement result. Whenever decisions are based on measurement results, it is important to have some indication of the quality of the results. In every area concerning with noise measurement many standards are available but without an expression of uncertainty, it is impossible to judge whether two results are in compliance or not. ISO/IEC 17025 is an international standard related with the competence of calibration and testing laboratories. It contains the requirements that testing and calibration laboratories have to meet if they wish to demonstrate that they operate to a quality system, are technically competent and are able to generate technically valid results. ISO/IEC 17025 deals specifically with the requirements for the competence of laboratories performing testing and calibration and for the reporting of the results, which may or may not contain opinions and interpretations of the results. The standard requires appropriate methods of analysis to be used for estimating uncertainty of measurement. In this point of view, for a testing laboratory performing sound power measurement according to specific ISO standards and European Directives, the measurement of uncertainties is the most important factor to deal with. Sound power level measurement, according to ISO 3744:1994 , performed with a limited number of microphones distributed over a surface enveloping a source is affected by a certain systematic error and a related standard deviation. Making a comparison of measurement carried out with different microphone arrays is difficult because results are affected by systematic errors and standard deviation that are peculiarities of the number of microphones disposed on the surface, their spatial position and the complexity of the sound field. A statistical approach could give an overview of the difference between sound power level evaluated with different microphone arrays and an evaluation of errors that afflict this kind of measurement. Despite the classical approach that tend to follow the ISO GUM this thesis present a different point of view of the problem related to the comparison of result obtained from different microphone arrays.