Liu C, Sideman S
Julius Silver Institute, Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
J Acoust Soc Am. 1996 Aug;100(2 Pt 1):848-56. doi: 10.1121/1.416245.
Microphone arrays with fixed optimum weights are known to suppress the background noise and reverberation that severely reduce the effectiveness of conventional hearing aids. By means of a general technique for digital frequency-domain implementation of optimum broadband arrays that was developed recently [C. Liu and S. Sideman, J. Acoust. Soc. Am. 98, 241-247 (1995)], a practically promising system is proposed to realize the arrays with the well-known sensitivity-constrained superdirective beamforming weights, and with five identical omnidirectional, cardioid, hypercardioid, or dipole microphones, respectively, in the endfire or broadside configurations, which were theoretically proposed by Stadler and Rabinowitz [J. Acoust. Soc. Am. 94, 1332-1342 (1993)]. The digital broadband frequency-domain beamforming system allows the broadband superdirective beamforming weights to be faithfully and independently applied to each frequency component of the signal. The practical application of this technique is demonstrated through computer simulation of the system in anechoic situations. Furthermore, its performance in simulated reverberant environments is evaluated.
已知具有固定最优权重的麦克风阵列能够抑制背景噪声和混响，而背景噪声和混响会严重降低传统助听器的效能。借助最近开发的一种用于最优宽带阵列数字频域实现的通用技术[C. 刘和S. 西德曼，《美国声学学会杂志》98, 241 - 247 (1995)]，提出了一种实际可行的系统，以实现具有著名的灵敏度约束超指向性波束形成权重的阵列，最终分别采用五个相同的全向、心形、超心形或偶极子麦克风，处于端射或侧射配置，这是由施塔德勒和拉宾诺维茨[《美国声学学会杂志》94, 1332 - 1342 (1993)]从理论上提出的。数字宽带频域波束形成系统允许将宽带超指向性波束形成权重忠实地且独立地应用于信号的每个频率分量。通过在消声情况下对系统进行计算机模拟，展示了该技术的实际应用。此外，还评估了其在模拟混响环境中的性能。
