Signal Transient Evoked Otoacoustic Emission Simulation And Signal Processing

It is one of significant research progresses to the otoacoustic emissions (OAE) in otology in the past20years,which is a phenomenon that is generated in the cochlea and audio energy release into the external auditory canal. It is generated initiatively by the outer hair cells in the inner ear cochlea, and is released by the form of vibrations in the air, It is the result of the role of cochlear nonlinear dynamical mechanism and an energy leakage of the outer hair cells in the nonlinear biological institutions amplification process. It is not a simple acoustic reflex physical phenomena. It not only converte external acoustic signal into biological signals passively but also release energy actively. So it is a two-way transducer. Its response characteristic is an objective evaluation of auditory peripheral system is intact or not. It is one of the important human physiological signals. In recent years clinical otoacoustic emission is mainly used to listen to physiological research, the auditory disease diagnosis and newborn hearing screening. Otoacoustic emissions has fine long-term stability, but its signal processing technology is still weak, the main problem is the noise removal and artifact elimination.This article focuses on the above problems, the main work includes the following aspects:(1)This paper discusses the feature of simulation otoacoustic emission signal. The fine agreement Transiently Evoked Otoacoustic Emission(TEOAE) signal to clinical testing is researched in the waveform, waveform amplitude and duration time by computer simulation(2) By the method of comparing with the traditional Fourier transform and wavelet analysis theory and method the availability of TEOAE denoising is researched by wavelet analysis method.Though theoretical analysis and experimental study.this paper draws the following conclusion:(1) According to the otoacoustic emission signal classification, characteristics, current problems and research methods,the wavelet analysis method is further researched by comparing with the traditional method.(2) On the basis of wavelet analysis method, firstly the denoising effect of TEOAE is compared between hard threshold and soft, the simulation experiment results were analyzed by selecting different threshold rules and in proportion to the size of the threshold. on the basis of the above, the simulation to the TEOAE that contains noisy is done by selecting the different wavelets wavelet basis, vanishing moments, decomposition level.(3) By the analysis of the experimental results, soft threshold denoising is selected in the Noise removal to TEOAE, minimax (minamaxi). the basic pattern of unknown size (SLN)is selected to the threshold changing size. And the Porgy is symN or coifletN, each vanishing moments is8and8, decomposition level is3.