Adaptive Headset ANC That Preserves Wanted Ambient Sounds
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Solution Overview
Problem
Existing active noise cancellation technologies suppress all external sounds to the maximum extent, preventing users from hearing desired information.
Innovation Solution
An active noise cancellation method that determines a wanted signal of interest and removes it from an ambient audio signal using an adaptive filter, allowing the phase-inverted signal to cancel noise while retaining the wanted signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If active noise cancellation suppresses all external sounds to the maximum extent, then noise cancellation effect is improved, but user's ability to hear desired information is lost
Solution Approach 1:
The patent segments the audio signal processing into distinct stages: first separating the ambient audio signal into noise components and desired signal components, then applying noise cancellation only to the noise components while preserving the desired signal components. This segmentation allows selective noise cancellation that maintains user awareness of important sounds.
Solution Approach 2:
The patent applies different processing qualities to different parts of the audio signal. The noise cancellation algorithm applies strong suppression to noise components while applying minimal or no processing to desired signal components. This local differentiation ensures that noise is reduced where needed while preserving information where it matters.
2Loss of information
If headset volume is increased to cover environmental noise, then user can hear music or audio content, but hearing fatigue is caused
Solution Approach 1:
The patent converts the harmful ambient noise into a useful resource by using it as the reference signal for active noise cancellation. The noise that would otherwise be unwanted is actually used to generate the anti-noise signal, transforming the problem into the solution. This allows the headset to cancel noise without requiring high volume settings.
3Adaptability or versatility
If adaptive filter processes the reference signal to obtain phase-inverted signal, then noise cancellation with desired signal retention is achieved, but device complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the headset continuously monitors the working status and adjusts the noise cancellation parameters accordingly. The system uses feedback from the environment and user needs to dynamically adjust the adaptive filter, allowing versatile noise cancellation while managing complexity through intelligent control.
Solution Approach 2:
The patent performs preliminary signal separation and classification before applying noise cancellation. By pre-processing the audio signal to identify and separate noise components from desired signals, the system prepares the data in advance for targeted processing. This preliminary action reduces the complexity of the main noise cancellation operation.
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
Effectively cancels ambient noise while allowing the user to hear desired sounds, enhancing user experience by reducing hearing fatigue.
Implementation Method 1
Active noise cancellation is based on a sound wave superposition principle, that is, noise removal is implemented through mutual cancellation of sound waves
Data Source
AI summary
The present discloser relates to a method for active noise cancellation. An example method includes: capturing an ambient sound to determine an ambient audio signal; and determining a working status, determining at least one corresponding wanted signal based on the working status, and then removing the at least one wanted signal from the ambient audio signal, to obtain a reference signal, where the wanted signal includes content of interest. The example method further includes determining a to-be-played signal based on the reference signal.