| 摘要 |
PROBLEM TO BE SOLVED: To detect periodic outbreak sound in a manner of accurate and a short delay time, and thereby to make it possible to appropriately respond on the basis of the detected noise.SOLUTION: A noise detection device 100 sections input sound data into frames with a predetermined time width, detects outbreak sound per frame, and determines periodicity of the detected outbreak sound, to detect periodic outbreak sound. The outbreak sound is detected by use of a duration time at a peak position and the amount of change in a peak. The periodicity of the outbreak sound is determined by an autocorrelation value in an outline-modeled waveform of the outbreak sound and evenness of time width of the waveform. A noise reduction device 500 performs sound pressure amount adjustment corresponding to a voice signal inclusion rate per frame to the detected periodic outbreak sound, and thereby reduces noise. Communication devices 200, 600 give notice on the basis of the detected periodic outbreak sound and make telephone calls with reduced noise. |
