Acoustic Signal Processing Device Noise Reduction
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Solution Overview
Problem
Existing acoustic signal processing technologies face challenges in effectively reducing noise with a small amount of prior information, particularly in environments where precise transfer characteristics between sound sources and microphones are difficult to identify.
Innovation Solution
An acoustic signal processing device and method that transforms acoustic signals into the frequency domain, calculates multiple sets of filter coefficients to minimize residual noise based on phase differences between channels, and uses singular value decomposition to optimize filter coefficients for noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If active noise control uses an adaptive filter to reduce noise, then noise reduction is achieved, but the filter coefficient does not necessarily become a comprehensive optimum solution and may suppress target sound as well as noise
Solution Approach 1:
The patent segments the noise reduction problem into two distinct components: a first filter for general noise reduction and a second filter specifically designed to protect target sound. This segmentation allows each filter to optimize for its specific function without interfering with the other, preventing target sound suppression while still achieving noise reduction.
Solution Approach 2:
The patent implements dynamic adaptation by continuously updating the first filter coefficient based on the difference between the original acoustic signal and the signal after second filter processing. This dynamic adjustment ensures the system adapts to changing acoustic environments while maintaining protection of target sound through the second filter.
2Measurement precision
If sound source separation technique is used to separate noise components, then separation precision can be improved, but it requires high precision transfer function identification which is difficult in actual environments
Solution Approach 1:
The patent implements a self-service mechanism where the system automatically estimates the transfer function between the acoustic signal and the noise signal using the processed output from the second filter. This eliminates the need for external or pre-configured transfer function data, allowing the system to adapt autonomously to the specific acoustic environment without requiring complex external identification processes.
3Object-affected harmful factors
If multiple filters are used to protect target sound while reducing noise, then noise reduction effectiveness improves, but computational complexity increases
Solution Approach 1:
The patent maintains continuous useful action by continuously updating the first filter coefficient using the output difference from the second filter processing. This continuous adaptation allows the system to maintain optimal noise reduction performance without requiring periodic recalibration or complex batch processing, thereby managing computational complexity through steady-state operation.
Data Source
AI summary
An acoustic signal processing device includes a frequency domain transform unit configured to transform an acoustic signal to a frequency domain signal for each channel, a filter coefficient calculation unit configured to calculate at least two sets of filter coefficients of a filter for each section having a predefined number of frames with respect to a sampled signal obtained by sampling the frequency domain signal transformed by the frequency domain transform unit for each frame such that the magnitude of a residual calculated based on a filter compensating for the difference in transfer characteristics between the channels of the acoustic signal is minimized, and an output signal calculation unit configured to calculate an output signal of a frequency domain based on the frequency domain signal transformed by the frequency domain transform unit and at least two sets of filter coefficients calculated by the filter coefficient calculation unit.