| 摘要 |
PROBLEM TO BE SOLVED: To obtain a method in which the distortion and the noise are not present and which changes the pitch and the reproducing speed of an acoustic signal by determining optimal overlapping connection points while calculating means absolute errors of the acoustic signal and changing the pitch and the reproducing speed of the acoustic signal. SOLUTION: An analog /digital converter 14 converts an analog audio signal into a digital signal. Next, the digital signal is divided into acoustic frames in a pitch shifting processor 76 and the pitch and the reproducing speed of the digital signal in certain frames is changed. Next, the changed acoustic frame is overlappingly connected with unchanged acoustic frames so that the unchanged acoustic frames are overlapped with the end area of a pre-changed acoustic frame. This overlapping calculates a differential mean absolute error to minimize an audible noise. Or, the pitch and the reproducing speed are determined by defining the overlapping connection point as the best overlapping point in which the distortion and noise are not entirely present. |
