Crosstalk cancellation system (CCS), which plays an important role in a 3D audio system applied in different fields including virtual reality, is very non-robust to some disturbances caused by the listener’s head movement or rotation. The need for dealing with the robustness of designing crosstalk cancellation filters against these slight disturbances remains unsolved.
Crosstalk cancellation system separates individual sound from a mixed resource (Image by IOA).
Now, a research team from the Institute of Acoustics of the Chinese Academy of Sciences proposes a stochastic robust approximation crosstalk cancellation method based on random perturbation matrix, to enhance the performance of crosstalk cancellation in 3D audio reproduction via loudspeakers.
Mathematically, the crosstalk cancellation can be considered as an approximation problem with basic objective in the different forms, such as Minmax and Least mean squares(LMS).
In practical applications, the transfer function matrix is unavoidably influenced by some perturbations and errors due to misalignments, tiny head movement and so on. Instead of adopting common design criterion for crosstalk cancellation, researchers introduce random variable and use mathematical expectation as the objective function, thus converting the problem of crosstalk cancellation to the stochastic robust approximation problem.
From a statistical point of view, changes in the transfer function caused by all the uncertain disturbances or errors can be modeled as random variables subject to a certain distribution. A random variable matrix is introduced to characterize the variations of the transfer function matrix between the loudspeakers and the listener resulted from listener’s tiny head movement.
Commonly used as the evaluation measure for crosstalk cancelation performance, Channel separation (CHS) is computed in experimental simulations.
Compared with traditional crosstalk cancellation methods, experimental simulation results demonstrate that this stochastic approximation method can improve the crosstalk robustness, especially when the nominal transfer matrix is ill-conditioned.
The research team, which focuses on crosstalk cancellation in 3D audio, is led by Prof. LI Junfeng and Dr. XIA Risheng. Prof. LI Junfeng mainly concentrates on psychoacoustics, speech signal processing and 3D audio technology.
This research is supported by the National Basic Research Program of China (973 Program) (No.2013CB329302), the National Natural Science Foundation of China (No.11461141004, No.61271426), the Strategy priority Research Program of the Chinese Academy of Sciences (No.XDA06030100).
XU Huaxing, WANG Qia, XIA Risheng, LI Junfeng, YAN Yonghong. A Stochastic Approximation Method with Enhanced Robustness for Crosstalk Cancellation. Chinese Journal of Electronics(Volume 26, Issue 6), DOI:10.1049/cje.2017.09.035.
Institute of Acoustics, Chinese Academy of Sciences, 100190 Beijing, China