| 摘要 |
PURPOSE:To give an original stereophonic signal the best effect by converting a sound signal into a ternary signal and finding an autocorrelation value from the ternary value, finding a function envelope by its linear approximation, and detecting the delay time up to the attenuation of its envelope to a prescribed attenuation ratio. CONSTITUTION:Stereophonic signals L and R of left and right channels which are inputted from an input terminal 59 are added by a mixing circuit 50 and inputted to a music head detecting circuit 55. The detection terminal of this circuit 55 begins the detection of the head of music and detects it securely. Further, the mixed stereophonic signal is sent to a ternary wave converting circuit 51 and converted into the ternary value. The ternary wave is inputted to a microcomputer 23 in synchronism with a clock for conversion and the sound source signal which is converted into the ternary wave by the circuit 51 is sent to an autocorrelation calculating circuit to calculate the correlation. Then, an envelope extracting circuit 53 finds the function envelope of linear approximation and the output of a comparator 54 is processed by a controller 56 to calculate the best delay time. Consequently, a control signal which sets the reverberation time of the delay time of the best initial reflected sound is sent to an initial reflected sound generating circuit 3 and a reverberation generating circuit 4. |
