Microphone Arrays for Immersive Voice Communications

沉浸式语音通信以低成本有效地促进了小组协作和电话会议。它正在成为现代通信网络的一个组成部分。沉浸式语音通信系统的一个关键技术挑战是获取高保真声学、音频和语音信号的能力，同时保持源的空间信息完整，以便远程听者能够感知声学环境，跟随一组说话者，并通过听信号的再现来区分他们。为了获得高保真语音并保持声音的真实感，有必要使用麦克风阵列。虽然麦克风阵列处理已经研究了几十年，但现有的技术产生频率相关的响应，这可能会对感兴趣的信号、噪声、干扰和声音真实感造成很大的失真；因此，它们不足以用于沉浸式通信系统。因此，本提案旨在解决麦克风阵列设计和波束形成的技术问题，并发展理论、方法和技术，以允许为沉浸式语音通信系统获取、处理和再现高保真空间声音。本方案包含以下关键技术创新和优点：1)频率不变麦克风阵列设计和信号波束形成的基本公式和信号处理理论，频率范围为60hz至20khz。2)新一代线性传声器阵列设计和频率不变和鲁棒波束形成技术。3)新一代圆形和球形传声器阵列设计及频率不变和鲁棒波束形成算法。4)在给定性能标准下优化传声器阵列几何结构的信号处理理论。5)分布式麦克风阵列处理的信号处理理论和新一代技术。6)一个实用的系统，以无处不在的声学信号为输入，产生高保真的输出信号，具有源真实感和可识别的源身份。很明显，拟议的研究是沉浸式语音通信的核心。由此产生的技术可以有广泛的应用，除了沉浸式语音通信，包括远程协作，人机界面，声学监控，安全，智能手机，智能家居系统，平板电脑，助听器等。随着对麦克风阵列的需求越来越大，该项目的研究成果无疑将对社会产生深远的影响，将是真正不可或缺的。

Immersive voice communication facilitates group collaborations and teleconferencing efficiently at lowcosts. It is becoming an integral part of modern communication networks. A key technical challengefor an immersive voice communication system is the ability to acquire high-fidelity acoustic, audio, andspeech signals while keeping spatial information of the sources intact so that it is possible for the remote listenerto sense the acoustic environment, follow a panel of talkers, and distinguish them by listening to thereproduction of the signals. To acquire high-fidelity speech and preserve the sound realism, it is necessaryto use microphone arrays. Although microphone array processing has been studied for a few decades,existing techniques produce frequency-dependent responses, which may cause much distortion to the signalof interest, noise, interferences, and sound realism; as a result, they are not sufficient forimmersive communication systems. This proposal is therefore organized to address the technical issues ofmicrophone array design and beamforming and develop theory, methods, and technologies that can allowacquisition, processing, and reproduction of high-fidelity spatial sound for immersive voice communicationsystems. This proposal contains the following key technical innovations and merits.1) A fundamental formulation of and a signal processing theory for frequency-invariant microphonearray design and beamforming for signals with frequency range from 60 Hz to 20 kHz.2) A new generation of technologies for linear microphone array design and frequency-invariant androbust beamforming.3) A new generation of circular and spherical microphone array design and frequency-invariant androbust beamforming algorithms.4) A signal processing theory for optimization of microphone array geometry with some given performancecriteria.5) A signal processing theory and a new generation of technologies for distributed microphone arrayprocessing.6) A practical system that takes ubiquitous acoustic signals as input and produces high-fidelity outputsignals with source realism and identifiable source identities.It is clear that the proposed research is in the heart of immersive voice communication. The resultingtechnologies can have a broad range of applications besides immersive voice communication includingtelecollaboration, human-machine interfaces, acoustic surveillance, security, smartphones, smart homesystems, tablet PCs, hearing aids, etc. As the demand of microphone arrays is increasing, the researchresult of this project will have undoubtedly a profound impact on the society and it will be truly indispensable.