| 摘要 |
PURPOSE:To exactly extract the feature amount of a frequency envelop component by deciding it according to the change of information entropy whether a predictive error signal is a pitch signal or not, and retroacting the process of generating an acoustic signal. CONSTITUTION:A second step MEM analysis part 23 further executes MEM analysis to a predictive error signal S3 sent from a first step MEM analysis part 21, sends information entropy S4 calculated from the predictive error signal S3 to an optimum degree decision part 25, and sends a predictive coefficient S6 of an optimum degree S5 for the second step MEM analysis part 23 sent from the optimum degree decision part 25 to a pitch frequency calculation part 24. While utilizing the character of rapidly changing when the information entropy calculated from the predictive error signal is enough for the degree or not enough, based on the information entropy S4 of the second step MEM analysis part 23, the optimum degree decision part 25 calculates the optimum degrees for the first step and second step MEM analysis parts 21 and 23. |
