The image source method (ISM) is often used to simulate room acoustics due to its ease of use and computational efficiency. The standard ISM is limited to simulations of room impulse responses between point sources and omnidirectional receivers. In this work, the ISM is extended using spherical harmonic directivity coefficients to include acoustic diffraction effects due to source and receiver transducers mounted on physical devices, which are typically encountered in practical situations. The proposed method is verified using finite element simulations of various loudspeaker and microphone configurations in a rectangular room. It is shown that the accuracy of the proposed method is related to the sizes, shapes, number, and positions of the devices inside a room. A simplified version of the proposed method, which can significantly reduce computational effort, is also presented. The proposed method and its simplified version can simulate room transfer functions more accurately than currently available image source methods and can aid the development and evaluation of speech and acoustic signal processing algorithms, including speech enhancement, acoustic scene analysis, and acoustic parameter estimation.

翻译：镜像源法（ISM）因其易用性和计算效率常被用于模拟房间声学特性。标准ISM局限于点声源与全向接收器之间的房间脉冲响应模拟。本文通过引入球谐指向性系数扩展了ISM，使其能够包含实际场景中安装在物理设备上的声源与接收换能器产生的声衍射效应。通过矩形房间内多种扬声器与麦克风配置的有限元仿真验证了所提方法的有效性。结果表明，所提方法的精度与房间内设备的尺寸、形状、数量及位置相关。此外还提出了一种可显著降低计算量的简化版本。所提方法及其简化版本相比现有镜像源法能更准确地模拟房间传递函数，可服务于语音增强、声场景分析与声学参数估计等语音及声学信号处理算法的开发与评估。