Acoustic and psychoacoustic analysis of the noise produced by the police force firearms.

UNLABELLED: Police officers are exposed to impact noise coming from firearms, which may cause irreversible injuries to the hearing system. AIM: To evaluate the noise exposure in shooting stands during gunfire exercises, to analyze the acoustic impact of the noise produced by the firearms and to associate it with tonal audiometry results. STUDY DESIGN: Cross-sectional. MATERIALS AND METHODS: To measure noise intensity we used a digital sound level meter, and the acoustic analysis was carried out by means of the oscillations and cochlear response curves provided by the praat software. 30 police officers were selected (27 males and 3 females). RESULTS: The peak level measured was 113.1 dB(C) from a .40 pistol and 116.8 dB(C) for a .38 revolver. The values obtained for oscillation and praat was 17.9 ± 0.3 Barks, corresponding to the rate of 4,120 and 4,580 Hz. Audiometry indicated greater hearing loss at 4,000Hz in 86.7% of the cases. CONCLUSION: With the acoustic analysis it was possible to show cause and effect between the main areas of energy excitation of the cochlea (praat cochlear response curve) and the frequencies of low hearing acuity.

Acoustic and psychoacoustic analysis of the noise produced by the police force firearms / Análise acústica e psicoacústica do ruído de armas utilizadas pela Polícia Militar

Police officers are exposed to impact noise coming from firearms, which may cause irreversible injuries to the hearing system. AIM: To evaluate the noise exposure in shooting stands during gunfire exercises, to analyze the acoustic impact of the noise produced by the firearms and to associate it with tonal audiometry results. STUDY DESIGN: Cross-sectional. MATERIALS AND METHODS: To measure noise intensity we used a digital sound level meter, and the acoustic analysis was carried out by means of the oscillations and cochlear response curves provided by the praat software. 30 police officers were selected (27 males and 3 females). RESULTS: The peak level measured was 113.1 dB(C) from a .40 pistol and 116.8 dB(C) for a .38 revolver. The values obtained for oscillation and praat was 17.9±0.3 Barks, corresponding to the rate of 4,120 and 4,580 Hz. Audiometry indicated greater hearing loss at 4,000Hz in 86.7 percent of the cases. CONCLUSION: With the acoustic analysis it was possible to show cause and effect between the main areas of energy excitation of the cochlea (praat cochlear response curve) and the frequencies of low hearing acuity.

Os policiais militares estão expostos a ruídos de impacto provenientes de armas de fogo, os quais são capazes de causar lesões irreversíveis ao sistema auditivo. OBJETIVO: Avaliar a exposição ao ruído no estande de tiros durante os exercícios de tiro, analisar acusticamente o ruído de impacto e relacioná-lo com os resultados de audiometria tonal. FORMA DE ESTUDO: Transversal. MATERIAL E MÉTODO: A medição do ruído foi feita por meio de decibelímetro digital e a análise acústica foi feita no software Praat, levantando as curvas de oscilograma e cocleograma. Foi selecionada uma amostra de 30 policiais militares (27 masculinos e 3 femininos). RESULTADOS: Os picos máximos medidos no estante de tiros foram de 113,1 dB(C) para pistola .40 e 116,8 dB(C) para revólver .38. Os valores obtidos por meio da relação entre o oscilograma temporal e cocleograma Praat ficaram entre 17,9±0,3 Barks, correspondendo à faixa entre 4120 e 4580 Hz. As medidas da audiometria indicaram maior perda auditiva na faixa de 4000Hz em 86,7 por cento dos casos. CONCLUSÃO: A partir da análise acústica dos tiros, foi possível demonstrar causa e efeito entre as principais áreas de excitação de energia na cóclea (cocleograma Praat) e as frequências com diminuição de acuidade auditiva.

Perfil audiológico em policiais militares do estado de São Paulo / Audiology profile in the military police state of São Paulo

Introdução: Os policiais militares constituem uma população exposta a ruído de impacto devido aos treinamentos com armas de fogo. Objetivo: Pesquisar o perfil audiológico em policiais militares do estado de São Paulo, e correlacionar à idade e o tempo de exposição com os achados audiológicos. Método: Neste estudo de série de casos, transversal, foi realizada avaliação audiológica em 200 policiais militares sendo 169 (84,5%) do gênero masculino e 31 (15,5%) do feminino, com idades entre 25 e 45 anos (média de 38,83±5,05), com média de tempo de serviço de 16,80±6,27 anos. Resultados: As principais queixas apontadas foram: zumbido (n= 52 / 26%), disacusia (n=36 / 18%), plenitude auricular (n=24 / 12%) e autofonia (n=24 / 12%). Na imitanciometria foram encontradas 100% de curvas tipo A (JERGER, 1970), e houve presença de recrutamento em 20 (10%) casos. Segundo os resultados da audiometria tonal, os dados obtidos demonstraram que 54 (27%) orelhas direita e 56 (28%) orelhas esquerda apresentaram perda auditiva. Os graus de perda com maior ocorrência foram 1 e 2 (MERLUZZI et al., 1979), com 85 (42,5%) casos. Houve correlação significativa entre a idade e o tempo de exposição com a piora dos limiares audiométricos em ambas as orelhas. Conclusão: A partir da análise dos dados audiológicos foi possível verificar que os policiais militares são uma população que apresenta risco para desenvolver a perda auditiva. Sendo assim, vemos a necessidade de implementação de programa de conservação auditiva para os policiais militares...

Introduction: The military police are a population exposed to noise impact due to training with firearms. Objective: To investigate the audiological profile of the military police in São Paulo state, and to correlate the age and duration of exposure and audiological findings. Method: In this study of case series, cross-sectional audiological evaluation was performed in 200 police officers being 169 (84.5%) were male and 31 (15.5%) females, aged between 25 and 45 years (mean 38.83 ± 5.05), average service time of 16.80 ± 6.27 years. Results: The main complains were: tinnitus (n=52/26%), hearing loss (n=36/18%), ear fullness (n=24/12%) and autophonia (n=24/12%). Impedance were found in 100% of type A curves (JERGER, 1970), and recruitment was present in 20 (10%) cases. According to the results of audiometry, the data showed that 54 (27%) right ears and 56 (28%) left ears had hearing loss. The degree of loss with higher prevalence was 1 and 2 (MERLUZZI et al., 1979), 85 (42.5%) cases. There was significant correlation between age and exposure time with the worsening of audiometric thresholds in both ears. Conclusion: From the audiological data analysis was possible that the military police are a population that presents a risk to develop hearing loss. Thus, we see the need for implementation of hearing conservation program for the military police...

Content-based retrieval of mammograms using visual features related to breast density patterns.

This paper describes part of content-based image retrieval (CBIR) system that has been developed for mammograms. Details are presented of methods implemented to derive measures of similarity based upon structural characteristics and distributions of density of the fibroglandular tissue, as well as the anatomical size and shape of the breast region as seen on the mammogram. Well-known features related to shape, size, and texture (statistics of the gray-level histogram, Haralick's texture features, and moment-based features) were applied, as well as less-explored features based in the Radon domain and granulometric measures. The Kohonen self-organizing map (SOM) neural network was used to perform the retrieval operation. Performance evaluation was done using precision and recall curves obtained from comparison between the query and retrieved images. The proposed methodology was tested with 1,080 mammograms, including craniocaudal and mediolateral-oblique views. Precision rates obtained are in the range from 79% to 83% considering the total image set. Considering the first 50% of the retrieved mages, the precision rates are in the range from 78% to 83%; the rates are in the range from 79% to 86% considering the first 25% of the retrieved images. Results obtained indicate the potential of the implemented methodology to serve as a part of a CBIR system for mammography.

Estudo comparativo entre tipos e tecnologias de scanners para a digitalizaçäo de mamogramas / Comparative study between types of scanners oand technologies for the digitalization of mammograms

O presente trabalho tem por objetivo determinar a tecnologia mais adequada para digitalizar mamogramas para processamento e classificação de microcalcificações mamárias, analisando os principais tipos e tecnologias de scanners, bem como os principais parâmetros de melhoria das imagens.