Patent Document ID: 4227177
Application ID: 05901006
Patent Flag: 1

Claim One:
1. In a speech analysis system for recognizing at least one predetermined keyword in an audio signal, each said keyword being characterized by a template having at least one target pattern, said target patterns having an ordered sequence and each target pattern representing at least one short term power spectrum, an analysis method comprising the steps of repeatedly evaluating electrical signals representing a set of parameters determining a short-term power spectrum of said audio signal within each of a plurality of equal duration sampling intervals, thereby to generate a continuous time ordered sequence of short-term audio power spectrum frames, repeatedly generating electrical signals representing a peak spectrum corresponding to said short-term power spectrum frames by a fast attack, slow decay peak detecting function, and for each short-term power spectrum frame, dividing the amplitude of each frequency band by the corresponding intensity value in the corresponding peak spectrum, thereby to generate a frequency band equalized spectrum frame corresponding to a compensated audio signal having the same maximum short-term energy content in each of the frequency bands comprising the frame, and identifying electrical signals representing a candidate keyword template when said selected multi-frame patterns correspond respectively to the target patterns of a said keyword template.