ON-LINE ADAPTIVE ALGORITHM TO ACOUSTIC FLUCTUATION FOR INVERSE FILTER RELAXATION IN SOUND REPRODUCTION SYSTEM

This paper proposes a on-line adaptive relaxation algorithm for in-verse filter. The inverse filter of the conventional method often am-plifies the background noise and line noise when the room transfer function changes. To resolve this problem, an iterative relaxation algorithm for inverse filter by truncated singular value decomposi-tion (Adaptive TSVD) have been proposed. However，it is diffi-cult to apply this relaxation method in a duration where the original signal contains the sound. Therefore, we extend Adaptive TSVD into an on-line type algorithm based on the observed signal at the only one control point，normalizing the observed signal with the original sound. The result of the simulation reveals that the pro-posed method can always carry out the relaxation process against to acoustic fluctuation in any time durations. Also, subjective evalua-tion in the real acoustic environment indicates that the sound quality improves without degrading the localization. 1