Concept and Perceptual Validation of Listener-Position Adaptive Superdirective Crosstalk Cancellation Using a Linear Loudspeaker Array
Journal article, 2019
This paper presents a multiband approach for crosstalk cancellation (CTC) based on superdirective near-field beamforming (SDB) that adapts dynamically to a change in the listener position. SDB requires the computation of a separate set of beamformer weights for each listener position. Our beamformer uses weights that exhibit a smooth evolution for listening positions along a linear trajectory parallel to the array. The beamformer weights can therefore be parameterized by using only a few parameters for each frequency. Upon real-time execution, the beamformer weights are determined efficiently for any position from the parameters with negligible error. Simulations and measurements show that the proposed method provides high channel separation and is robust with respect to small uncertainties of the listener position. A user study with 20 subjects and binaural signals shows consistent auditory localization accuracy across the different tested listening positions that is comparable to the localization accuracy of headphone rendering. The study also confirms the previously informal observation that fewer front-back confusions are observed when the listeners face away from the loudspeaker array compared to the listeners facing toward the array.