US 11,721,316 B2
Low-delay hybrid noise reduction system
Hao Ming Chen, Hsinchu (TW); and Ju Chieh Liu, Hsinchu (TW)
Assigned to STEADYBEAT TECHNOLOGY CORP., Hsinchu (TW)
Filed by SteadyBeat Technology Corp., Hsinchu (TW)
Filed on Apr. 18, 2022, as Appl. No. 17/723,164.
Claims priority of application No. 110145646 (TW), filed on Dec. 7, 2021.
Prior Publication US 2023/0178064 A1, Jun. 8, 2023
Int. Cl. G10K 11/178 (2006.01)
CPC G10K 11/17879 (2018.01) [G10K 11/17854 (2018.01); G10K 2210/3026 (2013.01); G10K 2210/3027 (2013.01); G10K 2210/3028 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A low-delay hybrid noise reduction system, comprising:
a reference audio receiving device for receiving reference source audio and outputting a reference source audio signal according to the reference source audio;
an error audio receiving device for receiving error source audio and outputting an error source audio signal according to the error source audio;
an audio output device for outputting a sound according to an audio signal received; and
an audio processing device connected to the reference audio receiving device, the error audio receiving device, and the audio output device, wherein the audio processing device comprises a feedforward noise reduction filter module, a feedback noise reduction filter module, and a mixer, the feedforward noise reduction filter module produces a feedforward noise reduction signal by performing feedforward noise reduction on the reference source audio signal received from the reference audio receiving device, the feedback noise reduction filter module produces a feedback noise reduction signal by performing feedback noise reduction on the error source audio signal received from the error audio receiving device, and the feedforward noise reduction signal and the feedback noise reduction signal are transmitted to the mixer, in order for the mixer to produce a noise reduction signal by mixing the feedforward noise reduction signal and the feedback noise reduction signal and output the noise reduction signal to the audio output device;
wherein the feedforward noise reduction filter module comprises a feedforward least mean squares (LMS) filter, a low-stage finite impulse response (FIR) filter, and 1st to Nth-stage biquad filters, the feedforward LMS filter updates a weight coefficient of the low-stage FIR filter according to the reference source audio signal received and the error source audio signal received, the 1st to the Nth-stage biquad filters perform low-delay filtering on the reference source audio signal received and output a filtered reference source audio signal to the low-stage FIR filter, and the low-stage FIR filter produces the feedforward noise reduction signal by performing self-adaptive modulation on the filtered reference source audio signal according to the updated weight coefficient and outputs the feedforward noise reduction signal.