SIGNAL DISCRIMINATION CIRCUIT

摘要

PURPOSE: To surely and highly accurately discriminate also a tone signal in addition to a voice signal or a voice band data signal at the time of discriminating them by a signal discrimination circuit. CONSTITUTION: The operation of a discrimination result output part 53 for judging whether the input signal S1 is a voice signal or a voice band data signal by a judged result S5 based upon the inter-block power rate of the input signal S1 and a judged result S6 based upon the frequency of zero crossing is controlled by an output S10 from a tone detection part 52 for calculating power by bands by the spectral analysis of the input signal S1 and judging the existence of a tone signal from the calculated power by bands, so that the tone signal can surely be discriminated from the voice signal at the time of inputting the tone signal.