ADAPTIVE DIRECTIONAL NOISE CANCELLING MICROPHONE SYSTEM

摘要

The present invention provides a noise cancelling microphone system which comprises an omni-directional microphone (1), a normal (e.g., cardioid-type) directional microphone (2), preamplifiers (3, 4), analogue-to-digital (A/D) converters (5, 6), an adaptive filtering circuit (7), a digital-to-analogue (D/A) converter (8) and a case (11) specially designed for the system. The omni-directional microphone (1) can receive the sounds from any directions with a same or very similar gain. The directional microphone (2) can receive sounds from the first directions, except the second directions, with a similar gain. The two microphones are combined together with a closely acoustically-coupled way.