Patent Document ID: 4592085
Application ID: 06469114

Base Claim:
1. A method for recognizing particular phonemes in a voice signal having silence-phoneme and phoneme-phoneme transitions, said method comprising the steps of: providing an electrical signal representing said voice signal; producing a first acoustic parameter signal from said electrical signal, said first acoustic parameter signal containing phonemic information of said voice signal; generating a transition signal from the phonemic information in said first acoustic parameter signal indicating the location in said voice signal of a transition; storing said first acoustic parameter signal; and producing a second acoustic parameter signal from said stored first acoustic parameter signal using said transition signal, said second acoustic parameter signal containing phonemic information of said voice signal at said transition, whereby said second acoustic parameter signal can be compared with known phonemic information to recognize the phonemic information in said voice signal.

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Claim 3:
3. A method for recognizing particular phonemes in a voice signal as in claim 1, wherein said step of generating comprises the sub-steps of: separating a plurality of time frames of said first acoustic parameter signal into a plurality of frequency band signals, each said frequency band signal representing a power level of said first acoustic parameter signal in a particular frequency band and time frame; calculating from said plurality of frequency band signals an average power level at each said time frame; calculating for all said time frames a plurality of first difference levels between said average power level at each said time frame and said plurality of power levels at the same time frame; calculating for all said frequency bands a plurality of second difference levels between: (1) the lowest of said first difference levels in each said frequency band for said plurality of time frames, and (2) each said first difference level in the same frequency band across said plurality time frames; and calculating the sum of all of said second difference levels, whereby said sum comprises said transition signal which can be evaluated to detect transitions in said voice signal.