Patent ID: 7184952

Claim:
A method of producing a substantially unintelligible, obfuscated speech signal from intelligible speech, comprising the steps of: obtaining a speech signal representing a speech stream; temporally partitioning said speech signal into a plurality of segments, said segments occurring in an initial order within said speech signal; selecting a plurality of selected segments from among said segments; and assembling said selected segments, in an order different than said initial order, to produce said obfuscated speech signal; wherein said segments represent phonemes within said speech stream; wherein said temporally partitioning step comprises the steps of: squaring said speech signal; calculating a short time average of said speech signal over a short time scale; calculating a medium time average of said speech signal over a medium time scale; calculating a difference between said short time average and said medium time average; and detecting zero crossings in said difference; wherein said zero crossings delineate said segments.