This paper seeks to enhance the quality of spatial sound reproduction by integrating two advanced signal processing technologies, active noise control (ANC) and three-dimensional (3D) audio, to a headset. The ANC module of the headset is designed based on the quantitative feedback theory (QFT), which is a unified theory that emphasizes the use of feedback for achieving the desired system performance tolerances in the face of plant uncertainties and plant disturbances. Performance, stability, and robustness of the closed-loop system have been taken into account in the loop-shaping procedure within a general framework of the QFT. On the other hand, 3D audio processing algorithms including the head-related-transfer-function and the reverberator are realized on the platform of a fixed-point digital signal processor. Listening tests were conducted to evaluate the proposed system in terms of various subjective performance indices. The experimental results revealed that the 3D headset is capable of delivering superior rendering quality of localization and spaciousness, with the aid of the ANC module.
Spatial sound reproduction systems using higher order loudspeakers
