Educação sonora: encontro entre ciências, tecnologia e cultura

Pós-graduação em Educação para a Ciência - FC

Parâmetros vocais perceptivo-auditivos e acústicos em crianças com nódulos vocais

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Measurement of Wave Attenuation in Buried Plastic Water Distribution Pipes

Leaks in pipes are a common issue encountered in the water industry. Acoustic methods are generally successful in finding and locating leaks in metallic pipes, however, they are less effective when applied to plastic pipes. This is because leak-noise signals are heavily attenuated due to high damping in the pipe-wall and sound radiation into the soil. As result, high frequency leak noise does not travel long distances. To determine how far leak noise may travel in a pipe at any frequency, the attenuation of the wave responsible for leak noise propagation should be known. In this paper a new method to estimate this is described. The method is then applied to some measurements made on a bespoke pipe-test rig in the UK, and the results are compared with theoretical predictions.

Perceptual and acoustic parameters of vocal nodules in children

Vocal nodules constitute the major cause of dysphonia during childhood. Auditory-perceptual and acoustic vocal analyses have been used to differentiate vocal nodules from normal voice in children.Purpose: To study the value of auditory-perceptual and acoustic vocal analyses in assessments of children with nodules.Design: Diagnostic test study.Patients and interventions: A comparative study was carried out including 100 children with videolaryngoscopic diagnosis of vocal nodules (nodule group-NG); and 100 children without vocal symptoms and with normal videolaryngoscopic exams (control group-CG). The age range of both groups was between 4 and 11 years. All children underwent auditory-perceptual vocal analyses (GRBASI scale); maximum phonation time and s/z ratio were calculated, and acoustic vocal analysis (MDVP software) were carried out.Results: There was no difference in the values of maximum phonation time and s/z ratio between groups. Auditory-perceptual analysis indicated greater compromising of voice parameters for NG, compared to CG: G (79 versus 24), R (53 versus 3), B (67 versus 23) and S (35 versus 1). The values of acoustic parameters jitter, PPQ shimmer, APQ, NHR and SPI were higher for NG for CG. The parameter f0 did not differ between groups.Conclusion: Compromising of auditory-perceptual (G, R, B and S) and acoustic vocal parameters (jitter, PPQ shimmer, APQ, NHR and SPI) was greater for children with nodules than for those of the control group, which makes them important methods for assessing child dysphonia. (C) 2013 Elsevier Ireland Ltd. All rights reserved.

Tool Condition Monitoring of Single-Point Dresser Using Acoustic Emission and Neural Networks Models

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

On the Acoustic Filtering of the Pipe and Sensor in a Buried Plastic Water Pipe and its Effect on Leak Detection: An Experimental Investigation

Acoustic techniques have been used for many years to find and locate leaks in buried water distribution systems. Hydrophones and accelerometers are typically used as sensors. Although geophones could be used as well, they are not generally used for leak detection. A simple acoustic model of the pipe and the sensors has been proposed previously by some of the authors of this paper, and their model was used to explain some of the features observed in measurements. However, simultaneous measurements of a leak using all three sensor-types in controlled conditions for plastic pipes has not been reported to-date and hence they have not yet been compared directly. This paper fills that gap in knowledge. A set of measurements was made on a bespoke buried plastic water distribution pipe test rig to validate the previously reported analytical model. There is qualitative agreement between the experimental results and the model predictions in terms of the differing filtering properties of the pipe-sensor systems. A quality measure for the data is also presented, which is the ratio of the bandwidth over which the analysis is carried out divided by the centre frequency of this bandwidth. Based on this metric, the accelerometer was found to be the best sensor to use for the test rig described in this paper. However, for a system in which the distance between the sensors is large or the attenuation factor of the system is high, then it would be advantageous to use hydrophones, even though they are invasive sensors.

Estudo e análise do coeficiente de absorção acústico do compósito da fibra de cana

Pós-graduação em Engenharia Mecânica - FEIS

Evaluation of hearing protection used by police officers in the shooting range

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

Correlação entre condição da superfície do solo agrícola e o coeficiente de absorção acústica

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

Association between interleukin-6 polymorphism in the-174 G/C region and hearing loss in the elderly with a history of occupational noise exposure

Introduction: The biological processes involved in noise-induced hearing loss (NIHL) are still unclear. The involvement of inflammation in this condition has been suggested.Objective: To investigate the association between interleukin - 6 (IL-6) polymorphism and susceptibility to NIHL.Methods: This was a cross-sectional study with a sample of 191 independent elderly individuals aged >60 years of age. Information on exposure to occupational noise was obtained by interviews. Audiological evaluation was performed using pure tone audiometry and genotyped through PCR by restriction fragment length polymorphism - PCR-RFLP. Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%.Results: Among elderly with hearing loss (78.0%), 18.8% had a history of exposure to occupational noise. There was a statistically significant association between the genotype frequencies of the IL-6 - 174 and NIHL. The elderly with the CC genotype were less likely to have hearing loss due to occupational noise exposure when compared to those carrying the GG genotype (OR = 0.0124; 95% CI 0.0023-0.0671; p<0.001).Conclusion: This study suggests there is an association of polymorphisms in the IL-6 gene at position - G174C with susceptibility to noise-induced hearing loss. (C) 2014 Associacao Brasileira de Otorrinolaringologia e Cirurgia Cervico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Sound absorption coefficient in situ: An alternative for estimating soil loss factors

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Origin and function of short-latency inputs to the neural substrates underlying the acoustic startle reflex

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

Firefighters' noise exposure: a literature review

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

Efeitos da variação do teor de umidade da madeira no processo de lixamento

The process of sanding wood is little known and industries use it in a practical way without having studied their best conditions before. There are few studies involving this type of machining. On this basis, this paper studied the effects of varying moisture content of the wood surface quality after the sanding process. It was used a sanding machine with flat horizontal cut parallel to the fibers, using: 02 different species (Pinus elliottii and Corymbia citriodora); 01 sanding abrasive (aluminum oxide) and 03 different particle size abrasives ( P80 , P100 and P120 ) . Initially, the pieces were acclimatized ( 2 ± 7% , 12% and 17% ± 2 ± 2 ) and subsequently passed by the sanding process, and therefore, the surface roughness was analyzed. For each condition, were performed 06 repetitions totaling 54 trials for each species. We analyzed the effects of wood moisture by capturing the power sanding, rougheness, acoustic emission and maximum temperature during the sanding process. The variation of moisture content produced changes in the surface quality of the finished parts, and these changes were more marked in Pinus than Corymbia. During the sanding process of the specimens with 7 % and 12 % humidity, there was a lower noise emission, power consumption and heating surface. When checking the roughness of these parts after this process, it was observed that the surface quality of them were superior in the parts sanded containing 17 % moisture

Zoneamento acústico urbano e mapeamento de níveis sonoros na zona central de Rio Claro (SP): diretrizes para o gerenciamento do ruído integrado ao planejamento ambiental urbano

Considering the growing degradation of the urban environmental quality resulting from the progressive sound pollution increase, as well as the consequent harmful effects about the human health, the present study had its central objective the argument and management tools implementation of the urban noise that can be integrated to the environmental planning in the city of Rio Claro (SP). Therefore, normative and bibliographical revisions were developed, that made feasible the directives of control argument and prevention of the urban noise, as well as the technical procedures of sound levels and evaluation’s definition and especially about the criteria applicable for the elaboration of an urban acoustic zoning methodology. Among the main results obtained detach: (1) the applicable legislation to the management of urban noise’s synthesis and argument; (2) the methodology of urban acoustic zoning development and (3) its implementation to determined areas of Rio Claro (SP) with the (4) respective cartography representation; (5) the mapping of sound levels in the central zone of Rio Claro (SP), (6) the obtaining and analysis of noise describers (LAeq, Lmáx, L10, L50, L90, Lmin and TNI) and the subsequent (7) acoustic maps elaboration for the main describers.