Method and arrangement for sound analysis

Abstract

For sound analysis, especially for speaker identification, a long-term spectrum is often formed from the recorded signal and compared to a long-term spectrum of a previously recorded signal. When the signal is, for example, received over telephone lines the transfer function thereof may distort the received signal to such an extent that identification is impossible. It is now proposed not to use the long-term spectrum for identification but rather its change, that is to say to accumulate the difference between two consecutive short-term spectra or the difference between such short-term spectrum and the long-term spectrum and to divide this accumulated value by the long-term spectrum in a Divider. Since the numerator and denominator each contain the frequency-weighting factor (a J ) of the telephone line transfer function, this factor is effectively cancelled out by virtue of the division operation performed in the Divider thereby eliminating the effect of the unknown transfer function. As a result the influence of the transfer function of the transmission path disappears almost completely.