A feedback active noise reduction system and method with flexible gain

Abstract

The invention provides a feedback active noise reduction system and method with a flexible gain. The noise reduction system comprises a microphone, a loudspeaker and a feedback filter unit. A transducer converts a sound signal of a position into an electric signal. The electric signal is inputted into the feedback filter unit and is processed to output a noise reduction signal. The noise reduction signal is converted into noise reduction sound wave through the microphone, the noise reduction sound wave and noise are superposed to generate destructive interference, and a noise reduction effect is achieved. At the same time, through monitoring an output amplitude of the feedback filter unit, a feedback filter gain is adjusted in an online way, the stability of the noise reduction system is ensured, and the robustness of the noise reduction system is enhanced.

Description

technical field [0001] The invention relates to the technical field of active noise reduction, in particular to a feedback active noise reduction system and method with flexible gain. Background technique [0002] Active noise reduction technology, also known as active noise reduction technology, is to neutralize the noise by generating sound waves with the same amplitude and opposite phase to the external noise through the sound generating device, so as to achieve the effect of noise reduction. According to the different topological structures, the methods adopted by active noise reduction are divided into two types: feedforward type and feedback type. The feedforward method uses the feedforward control method to design the noise reduction filter. This method does not have the problem of system stability, but the noise reduction depth is small, and the noise reduction effect is not obvious. The feedback type uses the feedback control method to design the noise reduction fi...

AI Technical Summary

Problems solved by technology

The feedforward method uses the feedforward control method to design the noise reduction filter. This method does not have system stability problems, but the noise reduction depth is small and the noise reduction effect is not obvious

The feedback type uses the feedback control method to design the noise reduction filter, the noise reduction depth is large, and the noise reduction effect is obvious, but there is a problem of system stability

[0003] Different noise environments have different noise frequency domain characteristics, so the noise reduction performance of the feedback filter with fixed parameters cannot be guaranteed. Moreover, the wearing habits of the noise reduction headset users will lead to differences in the acoustic characteristics of the noise reduction system. This difference will further deteriorate the noise reduction effect, resulting in feedback system overshoot or instability caused by howling

In this case, not only the noise cannot be eliminated, but the noise will also be enhanced

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