A Phase-Matched Exponential Harmonic Weighting for Improved Sensation of Virtual Bass

Virtual Bass System (VBS) is based on the psychoacoustic phenomenon called “missing fundamental” is widely used to extend the lower frequency limit of the small loudspeakers. The perceptual quality of the VBS is highly dependent on the weighting strategy for the generated harmonics. There have been several weighting strategies for the generated harmonics including loudness matching, exponential attenuation, and timbre matching. To precisely convey the weighting strategy, however, it is essential to match the phases between the reproduced harmonics to the natural harmonics contained in the original signal. In this paper limitations of the previous harmonic weighting schemes are addressed and a new harmonic weighting scheme is proposed. In the proposed weighting scheme, the slope of the attenuation weighting is dynamically varied according to the frequency of the missing fundamental, and a phase matching between the original and generated harmonics is performed prior to the harmonic weighting. Subjective tests show that the proposed method provides more natural and effective bass sensation than the conventional schemes.