Active noise cancellation method, active noise cancellation device and earphone

Abstract

Embodiments of the present application provide an active noise reduction method, an active noise reduction device, and an earphone. The method includes: in the coarse adjustment stage, filtering the reference noise signal, and fixing the filter coefficient unchanged to obtain a first inverse noise signal, and in a plurality of consecutive time periods, the first inversion noise signal in each time period is respectively Different time delays are performed on the signal to obtain multiple second anti-phase noise signals and output them to speakers for broadcasting to obtain multiple test residual noise signals; in the fine-tuning stage, the reference noise signal is filtered to obtain the third anti-phase noise signal Signal, use the primary selection delay to delay the third anti-phase noise signal, obtain the fourth anti-phase noise signal and output it to the speaker for broadcasting, where the primary selection delay is the minimum average energy among multiple test residual noise signals The delay corresponding to a test residual noise signal of , and the filter coefficients are updated. With this method, even if the sound source position changes, the filter coefficients can converge quickly and the convergence success rate is high.

Description

technical field [0001] The present application belongs to the technical field of active noise reduction, and in particular relates to an active noise reduction method, an active noise reduction device and an earphone. Background technique [0002] refer to figure 1 , In conventional active noise cancelling headphones, the external noise is collected by the reference microphone to obtain a reference noise signal, and the adaptive filter converts the reference noise signal into an anti-phase noise signal with the opposite phase and the same amplitude (ideally) as the external noise, Anti-phase noise is played by the speakers in the headphones. The external noise and the anti-phase noise are canceled (in fact, it is difficult to completely cancel) when the external noise is transmitted to the back of the human ear through the main channel. The error microphone collects the sound near the loudspeaker (ie residual noise) and sends the residual noise signal to the adaptive filte...

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Problems solved by technology

[0003] In the actual environment, due to the change of the position of the external noise source, the time delay and channel response of the external noise through the main channel will also change accordingly. If the adaptive filter cannot track and estimate in time, it will lead to the appearance of anti-phase noise and external noise. The deviation of amplitude and phase makes noise reduction fail

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