Patent ID: 9691407
Date: 2017-06-27
CPC Classifications: G10L

Claim:
1. A noise reduction apparatus comprising: a sensor configured to capture an input signal containing voice components; and a processor, wherein the processor performs processes comprising: extracting a signal in a section including a sudden sound from of the input signal that is input by the sensor before a current input signal is input, the sudden sound being a hitting sound having periodicity and having a signal level of voice components equal to or smaller than a predetermined threshold; storing a waveform of the extracted signal as sudden sound information in a storage; calculating a correlation value between the sudden sound information and the current input signal; calculating a phase difference between the sudden sound information and a sudden sound in the current input signal based on a maximum value of the correlation value; shifting a phase of the sudden sound information based on the phase difference and inverting a signal waveform of the sudden sound information to generate an addition signal; and adding the addition signal and the current input signal and thereby generating a signal in which the sudden sound in the current input signal is suppressed.