A Continuous-time Speech Enhancement Front-end for Microphone Inputs

Yoo, Heejong ; Ellis, Rich ; Anderson, David V. ; Hasler, Paul ; Graham, David W. ; Hans, Mat

HP Development Company

关键词: noise suppression;    speech enhancement;    analog VLSI;    low-power;   

RP-ID  :  HPL-2002-311

学科分类：计算机科学（综合）

美国|英语

来源: HP Labs

【 摘 要 】

In this paper, we present a real-time noise suppression system implemented with analog VLSI. The algorithm implemented is designed to reduce stationary background noise in single-microphone signals while preserving the non-stationary signal component. Because the system relies on analog computation rather than digital, it has benefits such as extremely low power consumption and real-time computation. The algorithm is based on an adaptive Wiener filter algorithm, adapted to take advantage of analog processing capabilities provided by floating-gate analog VLSI circuits. Noise suppression processing is performed on continuous-time signals in one-third octave subbands. The analog components described as parts of this system include a C^4 second-order section band-pass filter, peak and minimum detectors, a translinear division circuit, and a differential multiplier. Floating-gate circuits are used to set bias points and adjust offsets. 17 Pages