| 摘要 |
PROBLEM TO BE SOLVED: To judge a discrimination between a voiced part and a voiceless part of even a voice signal with a low signal-to-noise ratio and a voice signal containing non-stationarily generated noise. SOLUTION: A pitch correlation value calculation part 106 finds the pitch correlation between a frame to be processed and a frame having been processed in the past from an inputted voice signal. A decision part 107 judges no voice when the ratio of the power of the input signal and estimated noise spectrum power is less than a specific value, the spectrum distance between a voice spectrum and an estimated noise spectrum is less than a specific value, and the pitch correlation of the input signal is low. Further, the decision part 107 judges no voice when noise that the inputted voice signal contains dynamically varies, i.e., when the spectrum distance between the voice spectrum and a smoothed spectrum is less than a specific value and the pitch correlation of the input signal is low. |
