New models and approaches for the robust equalization of loudspeaker-room systems

随着多种形式的视听通信的日益存在，例如舒适的多声道免提电话的形式或通过为多媒体应用创建虚拟声音环境的形式，扬声器-房间系统的优化具有非常重要的实际意义。拟议研究的目的是探索设计这类系统的新方法，并以最佳方式实现空间体积的均衡。在申请人以前的工作中，已经成功地展示了如何通过根据给定的衰减曲线对总体响应进行整形来替换逆滤波范例来有效地均衡遭受严重混响的声学扬声器-房间系统。在理想情况下(例如，使用足够长的均衡器)，干扰混响可以减少到听不见的程度。在拟议的研究中，申请人开发的用于监听室均衡和串扰消除的稳健设计范例将被扩展，以便允许更大的收听者移动。为此，将发展新的位置相关系统扰动的统计模型和基于压缩传感的房间脉冲响应估计(内插、外推)方法，并将其纳入房间均衡。例如，目标是最小化所需测量的数量，同时实现与根据空间抽样定理对房间进行完整测量的几乎相同的稳健性。对于自适应解决方案，将使用光学跟踪系统捕获头部位置，并将其并入自适应均衡。这一适应为在混响环境中通过扬声器呈现3D音频奠定了基础，所提出的基于模型的方法有可能克服现有串音消除系统对几乎无回声房间的限制。性能的限制将在项目内进行调查。为了在滤波器设计过程中最大限度地利用现有的自由度，对伪影的感知将在算法设计中发挥重要作用。

With the growing presence of multiple forms of audio-visual communication, for example, in form of comfortable multi-channel hands-free telephony or by the creation of virtual acoustic environments for multimedia applications, the optimization of loudspeaker-room systems is of great practical importance. The objective of the proposed research is to investigate new approaches for the design of such systems and to enable the equalization of spatial volumes in an optimal way. In previous works of the applicant, it has been successfully shown how acoustic loudspeaker-room systems that suffer from severe reverberation can be effectively equalized by replacing the inverse-filtering paradigm by a shaping of the overall response according to a given decay curve. In ideal cases (e.g. with sufficiently long equalizers) disturbing reverberation can be reduced so far that it becomes inaudible. In the proposed research, the robust design paradigms for listening-room equalization and crosstalk cancellation developed by the applicant are to be extended in such a way that larger movements of listeners can be allowed. For this, novel statistical models for position-dependent system perturbations and compressed-sensing based methods for the estimation (interpolation, extrapolation) of room impulse responses are to be developed and incorporated into room equalization. The goal is, for example, to minimize the number of required measurements while achieving nearly the same robustness as with a complete measuring of the room according to the spatial sampling theorem. For adaptive solutions, the head position is to be captured with an optical tracking system and incorporated into an adaptive equalization. This adaptation founds the basis for the presentation of 3D audio via loudspeakers in reverberant environments, and the proposed model-based approach has the potential to overcome the limitations of existing crosstalk-cancellation systems to nearly anechoic rooms. The limits of performance are to be investigated within the project. To optimally exploit the existing degrees of freedom during filter design, the perception of artifacts will play an important role within the algorithm design.