Azimuthal Perceptual Resolution Model Based Adaptive 3D Spatial Parameter Coding

The spatial perceptual feature of human ears plays an important role on the quantization of spatial parameter. Human ears have the most sensitive feature for sound in frontal direction, less for the rear area, and least for the lateral sides. Traditional quantization method of spatial parameter for frontal channel pair in stereo spatial audio coding is not suitable for that of channel pairs in different directions such as lateral or rear directions in multichannel audio coding. An azimuthal perceptual resolution model based adaptive spatial parameter coding for 3D audio multichannel signals is proposed in this paper. Based on the omnibearing and non-uniform azimuthal perceptual resolution model of human ears for sound sources in different directions, quantization values of spatial parameters can be estimated adaptively according to the location and configuration of channel pairs in arbitrary directions. The density features of quantization steps for spatial parameters of channel pairs in arbitrary directions are corresponding to the non-uniform azimuthal perceptual resolution of human ears. So that the quantization noise can be effectively reduced under the directional perceptual threshold with the improved reproduced spatial sound quality.