Patent ID: 7081581

Claim:
Method for characterizing a signal, which represents an audio content, comprising: determining a measure for a tonality of the signal, wherein the tonality depends on the audio content, and wherein the tonality for a noisy signal differs from the tonality for a tone-like signal, wherein the step of determining a measure for the tonality comprises: calculating a block of positive and real-valued spectral components for the signal to be characterized; forming a quotient with the geometric mean value of a plurality of spectral components of the block of spectral components as numerator and the arithmetic mean value of the plurality of spectral components in the denominator, wherein the quotient serves as measure for the tonality, wherein a quotient with a value near 0 indicates a tonal signal, and wherein a quotient near 1 indicates an atonal signal with flat spectral curve; and making a statement about the audio content of the signal based on the measure for the tonality of the signal.