Time-frequency analysis applied to door slam sound quality problems

Abstract

Spectral analysis of non-stationary phenomena using traditional, segment averaged, discrete Fourier transform techniques suffers from limitations related to the trade-off between temporal and spectral resolution. These limitations are inherently due to the assumption of signal stationarity over an observation interval of fixed duration. In case frequency components occur in widely different frequency bands, an alternative technique, based upon the Wavelet transform, yields results with a temporal resolution which is inversely proportional to the analysis frequency. The issue of non-stationary spectral analysis is discussed at the hand of a sound quality problem related to a door slam. It is shown how the Wavelet analysis allows to identify the critical time instances and hence the critical physical phenomena responsible for the problem.

Echo Extraction from an Ultrasonic Signal Using Continuous Wavelet Transform

“…Wavelet transfOlm has already been shown as a useful tool for the interpretation and the enhancement of ultrasonic data in the context of nondestructive evaluation [1][2][3]. Main applications of the wavelet transfOlm are signal analysis in the time-frequency domain, data compression and now signal processing.…”

“…Main applications of the wavelet transfOlm are signal analysis in the time-frequency domain, data compression and now signal processing. Compm1sons with other time-frequency representations like short time Fourier transfOlm [1] and Wigner-ville transfOlm [2] have shown the usefulness of the continuous wavelet transfOlm for signal analysis: this method is well adapted to localize in time both high and low frequencies and does not introduce intel1'erence terms. Another important property is that signal reconstruction can be achieved from wavelet decomposition.…”