| 摘要 |
PROBLEM TO BE SOLVED: To provide a device capable of preventing duplication in a normal state by reproducing a second acoustic signal or the like embedded into an original acoustic signal when reproducing an acoustic signal duplicated by sampling the acoustic signal at a predetermined frequency or less.SOLUTION: A first acoustic frame of N samples is read out from a wide band acoustic signal and a second acoustic frame of M samples is read out from a second acoustic signal (S2, S3). First and second spectra are obtained from the first and second acoustic frames (S4, S5). Signal components of a frequency Ft or more out of signal components of the first spectrum are removed and signal components of the frequency Ft or less are positive-negative inverted, returned to a frequency direction of high band and added (S6). Signal components of the frequency Ft or more in the second spectrum are removed and signal components of the frequency Ft or less are returned to the frequency direction and combined with the signal components of the corresponding frequency of the first spectrum (S7). After frequency reverse conversion (S8), alternate samples are corrected and a low-frequency component is added to the corrected samples (S9, S10). |
