SIGNAL PROCESSING CIRCUIT AND SIGNAL PROCESSING METHOD, VOICE SIGNAL PROCESSING CIRCUIT AND VOICE SIGNAL PROCESSING METHOD, IMAGING APPARATUS AND VOICE SIGNAL PROCESSING METHOD OF IMAGING APPARATUS, RECORDING DEVICE AND RECORDING METHOD, AND REPRODUCING DEVICE AND REPRODUCING METHOD

摘要

PPROBLEM TO BE SOLVED: To reduce periodic noise whose period is variable from a voice signal in which periodic noise is mixed. PSOLUTION: A voice input signal S+N is input to a synchronous type adaptive filter 20 and a frequency adaptive type comb filter 10, then the periodic noise is eliminated on the basis of periodic information X by respective filters. In a selector 30, an input terminal is selected by the prescribed switching control signal, for example, an input terminal 30a is selected usually, when the periodic noise cannot be eliminated by the synchronous type adaptive filter 20, the input terminal 30b is selected and the periodic noise is eliminated by the frequency adaptive type comb filter 10. Thus, both of the frequency adaptive type comb filter and the synchronous type adaptive filter are used, when the period of the periodic noise is fixed, the synchronous type adaptive filter which does not affect a main voice signal so much is used, and when the period is changed, the frequency adaptive type comb filter having a high following property is used, thereby, the periodic noise can be effectively reduced. PCOPYRIGHT: (C)2007,JPO&INPIT