Near-field sound source signal pickup system based on microphone array

Abstract

The invention discloses a near-field sound source signal pickup system based on a microphone array, which is applied to a voice application system. The near-field sound source signal pickup system comprises a microphone array, a pre-amplification module, a phase tracking module and a sound source distance recognition module, wherein the microphone array comprises a first microphone, a second microphone and a third microphone which are linearly distributed at equal intervals and is used for picking up sound source signals in multiple channels, and the sound source signals comprise near-field sound source signals and far-field sound source signals; the pre-amplification module is used for performing pre-amplification on output signals of the first microphone, the second microphone and the third microphone; the phase tracking module forms and provides a tracking signal according to output signals of the pre-amplification module, and is used for tracking the far-field sound source signalspicked up by the second microphone and outputting the amplitude and phase of the signals after the pre-amplification; and the sound source distance recognition module forms a recognition signal according to the tracking signal, and the recognition signal suppresses the far-field sound source signals picked up by the microphone array. The sensitivity of the system decreases along with the increaseof the sound source distance, so that the system can effectively suppress the far-field sound source signals, and thus the signal-to-noise ratio of the picked up near-field source signals is improved.

Description

technical field [0001] The invention relates to a near-field sound source signal pickup system based on a microphone array. Background technique [0002] In order to effectively pick up near-field sound source signals in a noisy environment (the noise source is often in the far field), beamforming technology is usually used to make the sensitivity of the microphone array directional, that is, the sensitivity of the microphone array varies with the incident angle of the sound source. Variety. In actual use, the direction with the highest sensitivity of the microphone array is directed to the direction of the near-field sound source signal to be picked up, so that sound source signals (such as noise) in other directions can be suppressed to varying degrees. However, the directional microphone array can only distinguish the direction of the sound source and can hardly distinguish the distance of the sound source. Therefore, when the incident direction of the noise signal is ba...

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Problems solved by technology

However, when far-field sound source signals (such as noise) are vertically incident on the circular arc microphone array from the side, since the sound source signals arrive at each microphone at substantially the same time, the pickup of these far-field sound source signals will also be enhanced. , failed to suppress it; and, in the low frequency band, in order to obtain an effective interference effect between the microphones, the linearity of the arc-shaped microphone array should be equivalent to the wavelength of the sound wave, for example, the corresponding frequency is 100Hz sound wave, the wavelength is 3.4 meters , such a linear microphone array will lose its application value in most occasions

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