| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method and a device to determine the degree of voiced condition of multiplexed bands employing the frequency shifting method in a voice coder. SOLUTION: The method are composed of a step 100, in which a window is applied against inputted voice signals and a power spectrum is obtained from the voice spectrum obtained by Fourier transforming the windowing signals, a step 110, in which the power spectrum is divided into a prescribed number of subbands and the frequency is shifted to an original point for each subband, a step 120, in which the power spectrum that is frequency shifted to the original point is inverse Fourier transformed and an autocorrelation value is obtained for every subband, and a step 130 in which each autocorrelation value is normalized and the degree of voiced condition of every subband is determined from the normalized autocorrelation value.</p> |
