International Workshop on Hands-Free Speech Communication (HSC2001) April 9-11, 2001 Kyoto, Japan

Subtractive Beamformer Based on Paired-Microphones for Near-Field Sound Sources

Mitsunori Mizumachi and Satoshi Nakamura

ATR Spoken Language Translation Research Laboratories, Kyoto, Japan

A microphone array is very useful for hands-free speech communication. The near-field problem is a source of anxiety for beamforming techniques, and is discussed in this paper. We examine the performance of the formerly proposed method in the near-field condition, compared with the Delay-and-Sum beamformers. The proposed method can keep its performance high regardless of the distance between a sound source and an array, but the performance of the Delay-and-Sum beamformer declines even if an amplitude of a target signal is normalized. The concept of "&paired-microphone" in the proposed method is the key to solve the near-field problem.

Full Paper

Bibliographic reference.  Mizumachi, Mitsunori / Nakamura, Satoshi (2001): "Subtractive beamformer based on paired-microphones for near-field sound sources", In HSC2001, 79-82.