Real-time signal processing of noise data using cross-property techniques

Abstract

Before the advent of realtime one-third-octave analyzers, which give a better insight into different noise characteristics and provide a significant increase in the speed with which acoustic data can be processed, noise signals were analyzed in serial fashion into octave, one-third octave, or “narrow-band” results. More recently, narrow-band real time analysis techniques have provided an entire new dimension to our ability to interpret acoustic phenomena and isolate sources of noise. However, the most significant advance has undoubtedly been the introduction of the Fast Fourier Transform and its implementation in a real-time processing mode. This gives the ability to process signals with respect to their phase, as well as cause and effect, to a degree that was previously impossible. This paper deals with the application of two-channel signal processing techniques, using FFT, to several signal and system related measurement problems.