TONE SIGNAL DETECTOR, TONE SIGNAL DETECTION METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a tone signal detector suitable for reducing false detection of a tone signal due to noise.;SOLUTION: The tone signal detector has: a non-detection BPF 105 ; a detection BPF 107 having gain characteristics different from those of the non-detection BPF 105 ; a signal extraction BPF 111 for extracting a frequency component of a frequency corresponding to that of the tone signal from a supplied signal; a signal intensity detection section 112 and a control section 113 for determining whether the signal intensity of a signal extracted by the signal extraction BPF 111 exceeds a prescribed value, for outputting a non-detection signal when determining that the signal intensity does not exceed the prescribed value, and for outputting a detection signal when determining that the signal intensity exceeds the prescribed value; and a filter switch 109 for supplying a signal output from the non-detection BPF 105 and a signal output from the detection BPF 107 to the signal extraction BPF 111 while a non-detection signal and a detection signal are output, respectively.;COPYRIGHT: (C)2010,JPO&INPIT