ABSTRACT

This article gives a background idea of our works on the acoustic signal information processing, that is based not only on the lower order linear correlation but also on various types of the higher order nonlinear correlations. The importance of these higher order nonlinear correlations is discussed through the establishment of wide sense digital filters. These digital filters are essentially based on the Bayes theorem, which is expanded hierarchically by using the orthogonal polynomials. The present filters can estimate any kinds of statistics of arbitrary functional type of a state variable including the lower order statistics connected with the mater-side countermeasures and the higher order statistics connected with the delicate human-side evaluation indices.

The validity and the effectiveness of these filters are experimentally confirmed by applying them to real acoustic environmental problems.