Xu Zeyu, Herzog Adrian, Lodermeyer Alexander, Habets Emanuël A P, Prinn Albert G
International Audio Laboratories, Am Wolfsmantel 33, 91058, Erlangen, Germany.
Fraunhofer Institute for Integrated Circuits IIS, Am Wolfsmantel 33, 91058, Erlangen, Germany.
J Acoust Soc Am. 2024 Jan 1;155(1):343-357. doi: 10.1121/10.0023935.
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. These effects occur in practice when transducers are mounted on audio devices of finite spatial extent, e.g., modern smart speakers with loudspeakers and microphones. The proposed method is verified using finite element simulations of various loudspeaker and microphone configurations in a shoebox-shaped 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.
镜像源法（ISM）因其易用性和计算效率常被用于模拟室内声学。标准的ISM仅限于模拟点源与全向接收器之间的房间脉冲响应。在这项工作中，通过使用球谐指向性系数扩展了ISM，以纳入声衍射效应。当换能器安装在空间范围有限的音频设备上时，例如带有扬声器和麦克风的现代智能音箱，这些效应在实际中就会出现。通过对鞋盒形房间内各种扬声器和麦克风配置进行有限元模拟，验证了所提出的方法。结果表明，所提方法的精度与房间内设备的尺寸、形状、数量和位置有关。还提出了该方法的简化版本，它能显著减少计算量。所提方法及其简化版本能够比现有镜像源法更准确地模拟房间传递函数，有助于语音和声学信号处理算法（包括语音增强、声学场景分析和声学参数估计）的开发与评估。
