Open-Ear Acoustic Device Active Noise Cancellation
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Solution Overview
Problem
Existing acoustic devices, particularly open types, fail to effectively reduce environmental noise, leading to a poor user experience due to the interference of external sounds with audio content and voice calls.
Innovation Solution
An acoustic device comprising a microphone array, a processor, and at least one speaker, where the processor estimates a sound field at a target spatial position closer to the user's ear canal than the microphones, generates a noise reduction signal based on environmental noise and sound field estimation, and the speaker outputs a target signal to reduce environmental noise, while the microphone array is arranged to minimize interference from the speaker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If open acoustic devices are used to keep ears open for long-term wear, then comfort and ease of operation are improved, but noise reduction capability deteriorates due to large external noise interference
Solution Approach 1:
The system proactively generates anti-noise signals before the external noise fully interferes with the user's hearing. The microphone array captures environmental noise, the processor predicts the sound field at the ear canal position, and the speaker outputs anti-noise signals in advance to counteract the incoming noise, preventing rather than merely reacting to the harmful effect.
Solution Approach 2:
The patent introduces an intermediary sound field prediction mechanism between the external noise source and the user's ear. The microphone array and processor work together as intermediaries to capture, analyze, and predict the noise characteristics, then generate compensating signals that mediate the interaction between external noise and the user's hearing, reducing the harmful impact without blocking the ear canal.
2Object-affected harmful factors
If in-ear acoustic devices are used to block ears for noise reduction, then noise reduction capability is improved, but comfort deteriorates due to feelings of blockage and foreign body
Solution Approach 1:
The patent extracts the noise reduction function from the traditional in-ear blocking structure. Instead of using physical ear canal occlusion to achieve noise reduction, the system extracts the noise cancellation capability and implements it through open-ear speakers and microphone arrays, separating the noise reduction function from the blocking structure and enabling both open-ear comfort and effective noise reduction.
Solution Approach 2:
The patent replaces the mechanical ear canal blocking method with an acoustic field-based noise reduction system. The mechanical occlusion is substituted by electronic signal processing - microphones capture noise, processors predict and generate anti-noise signals, and speakers output these signals to cancel external noise acoustically, eliminating the need for mechanical ear blocking while maintaining noise reduction effectiveness.
3Measurement precision
If microphone array is placed closer to ear canal for better noise estimation, then measurement precision is improved, but device complexity increases due to interference from speaker output
Solution Approach 1:
The patent segments the acoustic device into functionally independent modules: microphone arrays positioned for optimal noise capture, speakers positioned for effective anti-noise output, and a processor that separately handles sound field prediction and signal generation. This segmentation allows each component to perform its function with minimal interference from others, reducing overall system complexity while maintaining measurement precision.
Solution Approach 2:
The patent applies local quality optimization by positioning the microphone array at specific locations where they can effectively capture environmental noise without being overwhelmed by speaker output interference. The microphones are placed in regions with favorable acoustic characteristics, and the processor uses sound field prediction to compensate for any residual interference, enabling high-precision noise estimation without requiring the microphones to be placed directly at the ear canal where speaker interference would be maximal.
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
The acoustic device effectively reduces environmental noise, enhancing the user's hearing experience by minimizing interference and maintaining open ears, thus improving audio quality and call clarity.
Implementation Method 1
The at least one speaker may be configured to output a target signal based on the noise reduction signal. The target signal may be used to reduce the environmental noise
Implementation Method 2
The microphone array may be configured to acquire an environmental noise
Data Source
AI summary
The present disclosure provides an acoustic device including a microphone array, a processor, and at least one speaker. The microphone array may be configured to acquire an environmental noise. The processor may be configured to estimate a sound field at a target spatial position using the microphone array. The target spatial position may be closer to an ear canal of a user than each microphone in the microphone array. The processor may be configured to generate a noise reduction signal based on the environmental noise and the sound field estimation of the target spatial position. The at least one speaker may be configured to output a target signal based on the noise reduction signal. The target signal may be used to reduce the environmental noise. The microphone array may be arranged in a target area to minimize an interference signal from the at least one speaker to the microphone array.