Patent ID: 6272106
Filing Date: 2001-08-07
Classification: H04B

Abstract:
A double talk detecting method applicable to an echo canceler which is employed in a telephone line network for performing a transmission between a speech coming through a four-wire circuit and another speech coming through a two-wire circuit, comprising:a first step of extracting a first speech pitch from a first speech signal corresponding to a speech on said four-wire circuit side, said first speech pitch being specified by a waveform of said first speech signal;a second step of extracting a second speech pitch from a second speech signal corresponding to a speech on said two-wire circuit side, said second speech pitch being specified by a waveform of said second speech signal;a third step of comparing said first speech pitch with said second speech pitch and judging whether or not a double talk is present, based on a result of the comparison;wherein said third step further comprises the steps of calculating correlation values of fluctuations of the speech pitches of said first and second speech signals; andjudging whether or not a double talk is present, based on said correlation values of fluctuations of the speech pitches of said first and second speech signals.