Coding of spatial sound fields

虚拟声学环境的实现是当前空间声学研究的发展趋势。VAES越来越广泛地应用于电影和音乐制作、电脑游戏以及医学科学中。借助最新的PC和数字信号处理技术的处理能力，可以以高级别的细节呈现复杂的虚拟世界。特别是在三维应用中，这导致了海量的数据，这对于实时信号处理、存储和传输是不切实际的。为了减少数据量，本研究方案的主要目标是一种球面声场的参数编码方法。实验的重点是用于房间模拟应用的球形麦克风阵列数据的双耳可听化。对于编码，数据在收听实验中被感知地评估，并且进一步与声场的物理属性相关。这种方法提取了各种感知参数和房间声学参数，这些参数对于描述房间声学质量是很重要的。它们为声场的参数表示提供了基础。在编码器中，多声道音频信号被下混合为单声道表示，该单声道表示与作为辅助信息的参数一起被传输到解码器。在这里，原始场景被重建。在实验中，考虑了各种阵列配置、房间、测试信号以及实际测量条件，如空间混叠或麦克风噪声。

The realization of virtual acoustic environments (VAEs) is a current trend in spatial audio research. VAEs are increasingly used in a wide range of applications, like in movie and music productions, computer games, as well as in medical science. With the processing power of up-to-date PC's and digital signal processing techniques it is possible to render complex virtual worlds in high grades of detail. Especially in three-dimensional applications, this leads to enormous amounts of data which are impractical for real-time signal processing, storage and transmission. In order to reduce the data, the main objective of this research proposal is a parametric coding approach for spherical sound fields. The focus of the experiments is on the binaural auralization of spherical microphone array data for room simulation applications. For coding, the data is evaluated perceptually in listening experiments and further related to the physical properties of the sound field. This way, various perceptual and room acoustical parameters are extracted, which are important for room acoustical quality description. They provide a basis for the parametric representation of the sound field. In the encoder, the multi-channel audio signals are down-mixed to a mono representation which is transmitted to the decoder, together with the parameters as side information. Here, the original scene is reconstructed. In the experiments, various array configurations, rooms, test signals, as well as realistic measurement conditions, like spatial aliasing or microphone noise, are taken into account.