| 摘要 |
PROBLEM TO BE SOLVED: To properly set a factor that represents the degree of reduction of noise components. SOLUTION: In a factor setting device, a noise reduction part 42 calculates amplitude ¾Y(f,τ)¾ of an acoustic signal y(t) by subtracting Kth power of amplitude ¾N(f,τ)¾ of each frequency f of a noise component n(t) (exponent K is a positive number of less than 0.1) from Kth power of amplitude ¾X(f,τ)¾ of each frequency f of an acoustic signal x(t). A reduction rate setting part 52 sets a target value N0 of a noise reduction rate NRR. An exponent setting part 54 sets the exponent K variably. A parameter setting part 56 calculates a shape parameterαof probability distribution which approximates strength distribution of the acoustic signal x(t) from the acoustic signal x(t). The factor setting part 58 calculates a reduction factorβvariably according to the target value N0 which is set by the reduction rate setting part 52, the exponent K which is set by the exponent setting part 54, and the shape parameterαwhich is set by the parameter setting part 56. COPYRIGHT: (C)2011,JPO&INPIT |
