VERFAHREN ZUR BESTIMMUNG EINES RAUSCHMODELLS IN EINEM GESTÖRTEN AUDIOSIGNAL

摘要

A process for the denoising of audio signals picked up in a noisy environment, for example in the cockpit of an aircraft or of another vehicle, and more precisely to the searching for a noise model in the audio signals. Input signals are digitized, and these signals are processed on the basis of a noise model, in principle with a view to eliminate as far as possible the noise corresponding to the model. The input signals are chopped into successive frames of P samples each, and a repetitive search for a noise model is performed continuously in the input signals themselves, by searching for N successive frames (N lying between a minimum N1 and a maximum N2) having the expected characteristics of a noise, by storing NxP corresponding samples so as to construct a noise model useful in the denoising processing of the input signals and by iteratively repeating the search so as to find a new noise model and to store the new noise model as a replacement for the previously stored noise mode or to retain the previously stored noise model according to the respective characteristics of the two models. The model is obtained by finding N frames whose energies are close to one another (ratio of energies lying between two values S and 1/S).