Effort Compression: Signal-Dependent Gain Management for the Pressure Matching Beamforming Method

Abstract

This work is focused on the trade-off between sound quality and loudspeaker gain that occurs when using the pressure matching beamforming method to generate stereo crosstalk cancellation with uniform linear arrays. An approach to gain management is proposed that leverages characteristics of subclasses of stereo audio signals (e.g. binaural) to partially overcome this tradeoff by improving both loudspeaker gain and sound quality together. The novelty of the proposed approach is based on an observation that loudspeaker gain management, which is normally accomplished by manipulating beamforming filters, can also be accomplished by manipulating input audio signals. It is shown that decoupling gain management from beamforming filters allows it to be signal-dependent. Also, that signal-dependent gain management gives beamforming filter designers more meaningful methods for controlling both the type and amount of sound quality that is sacrificed to manage gain. A general approach to building a signal-dependent gain management algorithm is suggested. Some specific implementations are given as examples. Finally, a discussion is presented about how signal-dependent gain management potentially establishes a future research project where perceived sound quality, as opposed to numerical sound quality, is maximized.