Psychoacoustic analysis and spatial coding of microphone array signals

用于测量和记录空间音频信号的麦克风阵列从来都不是完美的，这种测量误差会影响感知质量，例如声场再现。这些误差的例子包括麦克风噪声、阵列定位不准确、空间混叠、非心型麦克风特性等。到目前为止，这些误差仅在声学测量方面进行了分析和优化。该子项目将研究用于评估空间采样和传感器误差的心理声学方法，并使用这些方法创建用于估计感知质量的模型。该模型将用于改进麦克风阵列和有效存储空间声场，以进一步用于测量和听觉化。为了评估采样音频的空间质量，我们将研究一种适当的空间算法来进行平均，将空间、时间和频谱分辨率调整到人类听觉系统的分辨率。最后，将定义一种用于有效存储由麦克风阵列记录的空间音频信号的文件格式，并将实现原始测量数据的编码器。对于麦克风阵列测量误差与心理声学模型之间的相关性，将进行感知音频测量方法和听力测试。子项目将纳入子项目P2中获得的感知阈值知识，P7的声学属性以及P3和P8中进行的麦克风阵列和测量的准确性研究。

Microphone arrays used for measuring and recording of spatial audio signals are never perfect and this measurement error can affect the perceived quality for instance for sound field reproduction. Examples of such errors are microphone noise, positioning inaccuracies of the array, spatial aliasing, non-cardioid microphone characteristics, etc. Until now those errors have been analyzed and optimized with respect to acoustical measurements only. This subproject will investigate psychoacoustic methods for the evaluation of spatial sampling and sensor errors and use these methods for creating a model for the estimation of the perceived quality. This model will be used for the improvement of microphone arrays and also the efficient storage of spatial sound fields for the further use in measurement and auralisation. For the evaluation of the spatial quality of sampled audio a proper spatial algorithm to do an averaging adjusting the spatial, temporal and spectral resolution to the resolution of the human auditory system will be investigated. Finally a file format for the efficient storage of spatial audio signals recorded with microphone arrays will be defined and an encoder for the raw measurement data will be implemented.For the correlation between measurement errors from microphone arrays and psychoacoustic models perceptual audio measurement methods as well as listening tests will be performed. The subproject will incorporate the knowledge about perception thresholds obtained in subproject P2, the acoustic attributes of P7 and the accuracy studies of microphone arrays and measurement conducted in P3 and P8.