Simulation of an acoustic system using Power Envelope Inverse Filtering

In the present paper, we examine the development of a high-quality acoustics system called the sound field generation system (SFGS) using a power envelope inverse filtering (PEIF) proposed by the authors. PEIF is used for preprocessing of the SFGS, and we quantitatively evaluate SFGS using a real signal. When the output signal of SFGS is reproduced in the reproduction field, the effect of the SFGS is diminished due to the impulse response of reproduction field that is added to the created SFGS signal. Therefore, we attempted to reduce the influence of the reproduction field using a PEIF. In the experiment, we used five signals, namely, male speech, female speech, male vocal with music, female vocal with music, and classical music, and these signals were processed by computer simulation. We evaluated these signals by objective evaluation and subjective evaluation. In the objective evaluation, we obtained an improvement in SFGS for the results ranging from approximately 1 dB to 2 dB under 4 kHz, and up to 5 dB above 4 kHz. In the subjective evaluation, we obtained an improvement of approximately 10% to 60% in an experiment involving 52 subjects. These improvements are significant.