To reduce audible noise by detecting non-voice section in a time region, and attenuating signals in the non-voice section, in a voice signal of superposed noise.
A noise reduction method, for reducing audible noise from the noise signal of superposed noise over an entire region, has an input line for inputting a digital signal; a volume means for modifying the amplitude of an input signal; an average amplitude calculation means for finding the average amplitude of the input signal; an attenuation rate calculation means for modifying a threshold value by a currently set volume and finding an attenuation rate; a multiplication means for multiplying the attenuation rate obtained by the attenuation rate calculation means and the input signal; and an output line for outputting the digital signal.
| WO/2003/021572 | NOISE REDUCTION SYSTEM AND METHOD |
| JP3843743 | ROBOT AUDIO-VISUAL SYSTEM |
| JPH05134694 | VOICE RECOGNIZING DEVICE |
Tomoyasu Sakaguchi
Hiroki Naito