Katzberg Fabrice, Mazur Radoslaw, Maass Marco, Koch Philipp, Mertins Alfred
Institute for Signal Processing, University of Lübeck, 23562 Lübeck, Germany.
J Acoust Soc Am. 2017 May;141(5):3220. doi: 10.1121/1.4983093.
Closed-room scenarios are characterized by reverberation, which decreases the performance of applications such as hands-free teleconferencing and multichannel sound reproduction. However, exact knowledge of the sound field inside a volume of interest enables the compensation of room effects and allows for a performance improvement within a wide range of applications. The sampling of sound fields involves the measurement of spatially dependent room impulse responses, where the Nyquist-Shannon sampling theorem applies in the temporal and spatial domains. The spatial measurement often requires a huge number of sampling points and entails other difficulties, such as the need for exact calibration of a large number of microphones. In this paper, a method for measuring sound fields using moving microphones is presented. The number of microphones is customizable, allowing for a tradeoff between hardware effort and measurement time. The goal is to reconstruct room impulse responses on a regular grid from data acquired with microphones between grid positions, in general. For this, the sound field at equidistant positions is related to the measurements taken along the microphone trajectories via spatial interpolation. The benefits of using perfect sequences for excitation, a multigrid recovery, and the prospects for reconstruction by compressed sensing are presented.
封闭空间场景的特点是存在混响，这会降低免提电话会议和多声道声音再现等应用的性能。然而，准确了解感兴趣空间内的声场能够补偿房间效应，并在广泛的应用中提高性能。声场采样涉及对空间相关的房间脉冲响应进行测量，其中奈奎斯特 - 香农采样定理在时域和空域均适用。空间测量通常需要大量采样点，并且存在其他困难，例如需要对大量麦克风进行精确校准。本文提出了一种使用移动麦克风测量声场的方法。麦克风数量可定制，允许在硬件成本和测量时间之间进行权衡。总体目标是根据在网格位置之间用麦克风采集的数据，在规则网格上重建房间脉冲响应。为此，通过空间插值将等距位置处的声场与沿麦克风轨迹进行的测量相关联。文中介绍了使用完美序列进行激励、多重网格恢复的优点以及通过压缩感知进行重建的前景。
