基于缩尺模型的观演建筑视听一体化基础问题研究

Computer simulation of audio-visual integration technology can provide audio-visual experience. Comparing with computer simulation based on image source and ray tracing, the scaled model can simulate accurately in low frequency band. In this study, 3D scan and 3D print technology are applied to design a scaled dummy head which can receive audio and video signals. Firstly, the digital model of the scaled dummy head is built by 3D scanning technology with the standard artificial head as the prototype. The camera and microphone are built into the scaled dummy head by 3D editing software. Then the dummy head printed by 3D printer is placed in the audience seat of the architectural scale model. The combined auralization and visualization technology based on scale model is realized through convolution and playback. And subjective evaluation effected on acoustic and visual stimuli can be researched at the same time. This technology can be applied to audio-visual integrated evaluation experiment in the early stage of design. It can effectively improve the immersion in auralization experiment of scale model and be applied in architectural design widely.

计算机模拟的视听一体化技术可提供听音者直观的体验。与基于几何声学原理的虚声源法和声线跟踪法计算机仿真比较，缩尺模型考虑声音的波动特性，可在低频段精确模拟。本研究拟在观演建筑缩尺模型中采用3D扫描、编辑及打印技术，设计能接收声音和视频信号的缩尺人工头应用于视听一体化评价。首先通过3D扫描技术以标准人工头为原型建立缩尺人工头的数字模型 ，采用3D编辑软件将摄像头及传声器设计内置在缩尺人工头内，然后将设计好的数字模型用3D打印机制作缩尺人工头，通过对人工头在观演建筑模型观众席位置拾取的音频信号卷积处理与视频信号的同步回放，实现基于缩尺模型的视听一体化技术，同时研究在听觉激励和视听同时激励的条件下声音和图像的对应关系及主观听音的差异。该技术可在设计初期应用于视听一体化评价实验。运用该技术可有效提高观演建筑模型听音实验的沉浸感，促进缩尺模型视听一体化技术在观演建筑设计初期中的应用。

对于厅堂1:10缩尺模型实验来说，准确模拟足尺厅堂各界面材质来获取厅堂声学参数已是较成熟的技术，如何获得与真实足尺厅堂较为一致的可用于听音实验的双耳脉冲响应与虚拟视觉信号结合进行视听一体化评价是本项目研究的重点。为了使电火花声源得到的脉冲响应测试结果接近于MLS信号与扫频信号卷积出来的δ脉冲在厅堂的激励响应，项目组提出了一种在声学缩尺模型测试中利用高频电火花脉冲声源获得δ脉冲激励的新方法，改善了1:10缩尺模型可听化信号的音质，拓宽了可听化信号的频率范围。通过主观听音实验验证，应用该方法实现的可听化技术得到的音频信号可以显著优化交响乐队的听感。项目组以天津文化中心音乐厅为例，采用Odeon计算机仿真和1:10缩尺模型两种方法，结合VR虚拟现实模拟软件SimLab Composer进行了视听一体化评价研究，分别对比了基于Odeon软件仿真的多声源与单声源卷积的可听化信号分别在有无VR视觉信号的条件下的主观听音评价差别；基于1:10缩尺模型的听音信号分别在在无视觉条件下、屏幕显示视觉信号条件下、VR虚拟眼镜视觉信号条件下的主观听音评价差别。实验结果表明视觉条件对音乐厅音质的主观评价结果基本无影响。