Psychoacoustic experiments have shown that directional properties of the direct sound, salient reflections, and the late reverberation of an acoustic room response can have a distinct influence on the auditory perception of a given room. Spatial room impulse responses (SRIRs) capture those properties and thus are used for direction-dependent room acoustic analysis and virtual acoustic rendering. This work proposes a subspace method that decomposes SRIRs into a direct part, which comprises the direct sound and the salient reflections, and a residual, to facilitate enhanced analysis and rendering methods by providing individual access to these components. The proposed method is based on the generalized singular value decomposition and interprets the residual as noise that is to be separated from the other components of the reverberation. Large generalized singular values are attributed to the direct part, which is then obtained as a low-rank approximation of the SRIR. By advancing from the end of the SRIR toward the beginning while iteratively updating the residual estimate, the method adapts to spatio-temporal variations of the residual. The method is evaluated using a spatio-spectral error measure and simulated SRIRs of different rooms, microphone arrays, and ratios of direct sound to residual energy. The proposed method creates lower errors than existing approaches in all tested scenarios, including a scenario with two simultaneous reflections. A case study with measured SRIRs shows the applicability of the method under real-world acoustic conditions. A reference implementation is provided.

翻译：心理声学实验表明，房间声学响应中直达声、显著反射和晚期混响的方向特性对特定房间的听觉感知具有显著影响。空间房间脉冲响应（SRIRs）捕捉了这些特性，因此被用于方向相关房间声学分析和虚拟声学渲染。本文提出一种子空间方法，将SRIRs分解为包含直达声与显著反射的直接部分和残差部分，通过对这些分量提供独立访问以增强分析和渲染方法。该方法基于广义奇异值分解，将残差解释为需从混响其他分量中分离的噪声。较大的广义奇异值归属于直接部分，该部分随后被获得为SRIR的低秩近似。通过从SRIR末端向起始端推进并迭代更新残差估计，该方法适应残差的时空变化。本文使用空间频谱误差度量及不同房间、麦克风阵列和直达声与残差能量比的模拟SRIRs进行评估。该方法在所有测试场景（包括包含两个同时反射的场景）中均比现有方法产生更低误差。针对实测SRIRs的案例研究证明了该方法在真实声学条件下的适用性。文中提供了参考实现。