RESUMO

PURPOSE: Linear acoustic indices are significantly influenced by speaking voice intensity. The main aim of this work was to compare acoustic measures based on linear and nonlinear models in different speaking voice intensity levels and to analyze the reliability of those measures in different intensity levels in subjects with voice disorders. METHODS: 435 samples from subjects (314 women, 121 men with a mean age of 41.07 ± 13.73) diagnosed with various voice disorders were used. In total, 17 acoustic measures were derived from the vowel /ɛ/ sustained at three intensity levels (soft, comfortable, and loud). Five were linear (standard deviation of the fundamental frequency (f0), jitter, shimmer, harmonics-to-noise ratio (HNR) and smoothed cepstral peak prominence (CPPS)), and twelve were nonlinear measures, namely correlation dimension (D2), correlation entropy (H2), first minimum of the mutual information function (FMMI), relative entropy (ENTR-R), largest Lyapunov exponent (Lyap), determinism (DET), transitivity, mean diagonal line length (Lmed), Shannon entropy (ENTR-S), mean length of vertical structures, also known as trapping time (TT), laminarity (LAM) and recurrence period density entropy (RPDE). Differences between speaking voice intensity levels were assessed by Friedman's test and Nemenyi as posthoc test. Intraclass correlation coefficient was used to investigate if each acoustic measure remains in agreement (reliability) between different voice intensity levels. RESULTS: There were significant differences in all acoustic measures about vocal intensity level (P < 0.001). Intraclass correlation coefficient was very good for HNR (>0.61) and good for Lyap, DET, ENTR-S, Lmed, RPDE, and TT (0.41-0.60). CONCLUSIONS: All acoustic measures varied as a function of vocal intensity in voice disordered adults, while this relation was different for linear and nonlinear measures. Only the measures HNR, Lyap, DET, ENTR-S, Lmed, RPDE and TT had an acceptable reliability between different voice intensity levels. Therefore, patient`s voice SPL should be controlled or indicated during acoustic vocal assessment.

Assuntos

Fonação , Distúrbios da Voz , Adulto , Masculino , Humanos , Feminino , Pessoa de Meia-Idade , Qualidade da Voz , Reprodutibilidade dos Testes , Acústica da Fala , Medida da Produção da Fala/métodos , Distúrbios da Voz/diagnóstico , Acústica

RESUMO

Abstract Agricultural Machinery as an off-road vehicle is the backbone of the World agricultural industry. Its main function is to operate as a prime mover and support the power requirements to function the various type of draft implements. In this regards, the hydraulic system is an important part and is controlled by the propagated oil which is cleaned by impurities and debris using a filter system. Once it blocks, the bypass opens to avoid any pressure burst of the system, and the particles find their way into the hydraulic system and get lodged in the gears, pumps, valves, and drive train to hinder the performance of the Agricultural Machinery. This research presents an onboard Multiple Signal Classification Algorithm (MUSIC) and pseudo-spectrum analysis as a computational tool used by cellphones to analyze the particle pollution level of the hydraulic filter. This analysis is carried out on the soundtracks recorded from different cell phones in different incremental stages of fluid contamination to the particles until it being choked, based on the standard of ISO4406.

Assuntos

Acústica , Manutenção Preventiva/métodos , Hidráulica , Algoritmos , Erros de Diagnóstico

RESUMO

Abstract Introduction The present work aims to develop statistical models for the psychoacoustic behavior of human beings in lateralization judgments of binaural acoustic stimuli, as a function of Interaural Time Delay (ITD) and Interaural Amplitude Difference (IAD) for several Sensation Levels (SL). Such models intend to contribute to a deep comprehension of the perception or recognition mechanism which permits listeners to decide whether a source of a sound is located on the right or on the left side of their medial plane. Methods Numerous lateralization judgments are accomplished through a computer controlled experiment set-up in order to investigate the transduction mechanism beneath them. The statistical treatment of the psychoacoustic data obtained has been performed by Two and Three Factors – Probit (Probability Unit) Analysis. Results The Probit Analysis makes it possible to obtain the model coefficients and to fit ‘Probit Planes and Surfaces’ to the experimental data in order to study and predict the simultaneous effects produced by ITD and IAD in the listeners’ psychoacoustic perceptions at several Sensation Levels (SL). Conclusion The approach used here is appropriate for the analysis of this kind of binary response and it also offers a simple way to obtain psychophysical responses that can be related to neurophysiological phenomena. It is argued that this fact may lead to another way to access neural information through psychoacoustic experiments, without needing invasive methods.