Adaptive ANC Earpiece Filter Tuning for Variable Ear Fit
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Solution Overview
Problem
Active noise cancellation earphones are affected by varying ear canal structures and wearing methods, leading to inconsistent noise cancellation effects and user experience.
Innovation Solution
An adaptive noise cancellation method that determines and updates filter operation coefficients in real-time based on audio data and environmental conditions, using primary and secondary path transfer functions, without additional audio signals, to adjust noise cancellation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fixed filter parameters are used for noise cancellation, then the system is simple and fast to implement, but the noise cancellation effect deteriorates when wearing conditions or ear canal structures change
Solution Approach 1:
The patent implements dynamic filter parameter adjustment by continuously updating the filter coefficients based on real-time feedback from microphones. The system transitions from static fixed parameters to dynamic adaptive parameters that automatically adjust to changing wearing conditions and ear canal structures, maintaining optimal noise cancellation performance without manual intervention.
Solution Approach 2:
The patent employs feedback mechanisms where microphones capture ambient noise and the system uses this information to continuously adjust filter parameters. The feedback loop allows the system to monitor the actual noise cancellation effect and automatically optimize parameters, resolving the contradiction between reliability and complexity through automated adaptation.
2Reliability
If additional audio signals are added to improve noise cancellation, then the noise reduction effect is enhanced, but user experience deteriorates due to audio interference
Solution Approach 1:
The patent extracts and processes only the necessary audio information from the ambient noise signal itself, rather than adding separate test tones or signals. By using the ambient noise data directly to train and adjust filter parameters, the system achieves improved noise cancellation without introducing additional audio interference that would affect user experience.
Solution Approach 2:
The system uses the ambient noise signal to improve its own performance without requiring external assistance or additional signals. The ambient noise itself serves as the training data and feedback mechanism, allowing the noise cancellation system to self-optimize while avoiding the harmful effect of adding extra audio content that would interfere with music or voice calls.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures consistent noise cancellation across different wearing environments and user interactions, enhancing user experience by maintaining effective noise reduction without additional audio interference.
Implementation Method 1
Active noise cancellation earphones try to send out an audio signal with a similar amplitude and an opposite phase to the ambient noise through a speaker in the earphones to achieve an effect of offsetting the ambient noise
Data Source
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AI summary
An active noise cancellation method and active noise cancellation earphones are provided, which may improve a noise cancellation effect of the active noise cancellation earphones. The active noise cancellation earphones include an in-ear microphone, an out-of-ear microphone, a speaker and a filter, and the method includes: determining a first primary path transfer function according to a first out-of-ear data collected by the out-of-ear microphone and a first in-ear data collected by the in-ear microphone when the speaker plays audio data; determining audio data received by the in-ear microphone according to the first in-ear data, the first out-of-ear data and the first primary path transfer function; determining a first secondary path transfer function according to the audio data played through the speaker and the audio data received by the in-ear microphone; and updating an operation coefficient of the filter to a first operation coefficient according to the first primary path transfer function and/or the first secondary path transfer function.