| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem where an acquired impulse answer has an error and the wraparound elimination performance is deteriorated by a delay time due to the impulse answer being obtained from the signal of an observation point in an environment where the wraparound varies. SOLUTION: An estimation circuit 19, which estimates the current wraparound characteristic from the changed variables of impulse answers of past wraparound waves, is added to a coefficient updating circuit 18 in an FIR filter coefficient generating circuit 4. Thus, an estimation type coefficient updating circuit 17 is configured. In such a constitution, the deterioration of variance follow-up characteristic can be suppressed, even when the wraparound waves have time variances. |
