SIDETONE CANCELLATION METHOD AND SIDETONE CANCELER

摘要

PROBLEM TO BE SOLVED: To prevent a pseudo sidetone from being caused when a speech is made using any other device in a state that a device such as a telephone set which generates sidetones is not connected or a device such as a telephone set is not in a speech state. SOLUTION: A sidetone canceler 101 comprises: a variable filter section 102 for filtering a transmission signal x(t); a subtractor 104 for subtracting the output signal y'(t) of the variable filter section 102 from a reception signal y(t); a filter coefficient updating section 103 for updating the filter coefficient of the variable filter section 102 so as to reduce the mean square of the sidetone that is a transmission signal component included in the reception signal y(t); a sidetone detection section 105 for detecting presence/no presence of the sidetone on the basis of the filter coefficient; and a switch section 106 for selecting a signal e(t) when presence of the sidetone is determined and for selecting the receive signal y(t) when absence of the sidetone is determined. COPYRIGHT: (C)2011,JPO&INPIT