| 摘要 |
The process for slowing-down/speeding up a speech signal involves splitting at least a portion of the speech frequency bandwidth into N narrow sub-bands, processing each sub-band signal contents to derive therefrom magnitude data M(i, n) and phase data P(i,n), i= 1, ..,N being the subband index and n the time index. The M (i, n) sequence is converted into a sequence M'(n) by either duplicating one sample every K samples (K being an integer value derived from the desired slowing-down/speeding up ratio). The phase sequence P (i,n) is processed to derive therefrom an increment sequence D(i,n) = P(i,n) - P(i, n-1), which increment sequence is first converted into a D'(i, n) sequence by either dropping or duplicating one sample every K, samples, before being converted into P'(i,n) = P(i,n) + D'(i, n). Said P'(i,n), D'(i,n) sequences are converted back into sub-band signals contents, then combined together into the slowed-down/speeded-up speech signal. |
