Patent ID: 7373209

Claim:
A sound features extracting apparatus comprising: an audio signal input part which receives an audio signal of sound data including predetermined time frames; a first frequency analyzer which analyzes a plurality of frequency bands of each of the predetermined time frames of said audio signal received from said audio signal input part, and which outputs a signal for each of the frequency bands; a rise component calculator which detects a rise component in said signal of each of the frequency bands received from said first frequency analyzer, and which sums said rise components to determine a rise component for each time frame; an auto-correlation function calculator which calculates an auto-correlation function of said rise components; a second frequency analyzer which analyzes said auto-correlation function calculated by said auto-correlation function calculator, and which outputs a signal for each of the frequency bands; a direct-current component detector which detects a direct current component in said signal outputted from said second frequency analyzer; a peak detector which detects a signal of each of the frequency bands which is maximum in the power from said signal outputted from said second frequency analyzer; and a ratio calculator which divides the power of said output of said direct-current component detector by the power of said output of said peak detector, wherein said sound features extracting apparatus calculates a non-periodic property of sound emission which is a primary feature of said audio signal.