Real-time acoustic beamforming on a PC
A two-microphone adaptive beamformer is implemented in real-time on a personal computer. The language used is National Instruments LabView. This data-flow language is ideally suited for the rapid prototyping of this kind of application and uses two normalized least-mean squares (NLMS) algorithms together with a special voice-activity detector (VAD). The VAD defines an active zone directly in front of the microphones within which valid speech is assumed. Outside of this zone is assumed to be noise of any description. Typical applications of the method is for hearing aids or noise reduction in speech recognition systems.