Dynamic Noise Cancellation Using Spectrum Analysis
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Solution Overview
Problem
Existing noise-canceling earphones with fixed filtering coefficients fail to effectively address diverse environmental noises, leading to inconsistent noise cancellation across different environments.
Innovation Solution
An audio playback apparatus and method that includes a sound receiving circuit, storage circuit, filter control circuit, and audio playback circuit, which calculates stationary noise power spectrum density, determines noise spectrum distribution, and retrieves selected filter parameters to generate an anti-noise audio signal, allowing for dynamic noise cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed filtering coefficients are used in the anti-noise circuit, then the device complexity is reduced, but the adaptability to different environmental noises deteriorates
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting filtering coefficients based on noise spectrum distribution analysis. The system calculates noise power spectrum density, determines noise spectrum distribution, and selectively adjusts filtering coefficients according to different noise characteristics (e.g., low-frequency noise in airplanes vs. high-frequency noise on streets), thereby resolving the contradiction between fixed complexity and adaptability.
2Adaptability or versatility
If adaptive circuit configuration dynamically adjusts filtering coefficients, then the adaptability to different noises is improved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the noise cancellation process into distinct functional modules: noise signal acquisition, noise power spectrum density calculation, noise spectrum distribution determination, and selective filtering coefficient adjustment. This modular segmentation manages complexity by organizing the adaptive adjustment mechanism into manageable, independent stages.
Solution Approach 2:
The patent implements dynamics by making the filtering coefficients adjustable and adaptive rather than static. The system dynamically changes filtering coefficients based on real-time noise spectrum distribution analysis, allowing the anti-noise circuit to adapt to different environmental conditions while maintaining controlled complexity through systematic adjustment protocols.
3Adaptability or versatility
If adaptive circuit configuration is used, then the noise cancellation adaptability is improved, but the operational complexity increases
Solution Approach 1:
The patent applies self-service by enabling the anti-noise circuit to automatically analyze noise spectrum distribution and adjust filtering coefficients without user intervention. The system autonomously calculates noise power spectrum density, determines noise characteristics, and selectively adjusts parameters based on environmental conditions, eliminating the need for manual parameter tuning and simplifying operation.
Solution Approach 2:
The patent implements feedback by continuously monitoring noise signals, analyzing noise spectrum distribution, and using this information to adjust filtering coefficients. The system creates a closed-loop control mechanism where noise analysis results feed back into parameter adjustment, enabling automatic adaptation to changing environmental conditions without increasing operational complexity for the user.
Data Source
AI summary
The present disclosure discloses an audio playback apparatus having noise-canceling mechanism that includes a sound receiving circuit, a storage circuit, a filter control circuit, a filter circuit and an audio playback circuit. The sound receiving circuit receives received audio signal including noise. The storage circuit stores filter parameters. The filter control circuit includes a noise estimation circuit, a noise distribution determination circuit and a parameter generation circuit. The noise estimation circuit receives the received audio signal and calculates a stationary noise power spectrum density of the noise such that the noise distribution determination circuit determines a noise spectrum distribution accordingly. The parameter generation circuit analyses the noise spectrum distribution and retrieves a group of selected filter parameters accordingly. The filter circuit filters the received sound signal according to the group of selected filter parameters to generate an anti-noise audio signal. The audio playback circuit playbacks an actual audio signal and the anti-noise audio signal simultaneously.