Open-Ear Acoustic Devices With Microphone Arrays for Noise Reduction

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Solution Overview

Problem

Existing wearable audio devices, such as off-ear headphones, struggle with effective noise reduction and directional audio capture, leading to suboptimal user experience and limited acceptance among users, particularly for those hesitant to use hearing aids.

Innovation Solution

An open-ear acoustic device with an array of microphones and acoustic transducers that preferentially capture and deliver audio from a specific direction, utilizing an active noise reduction engine to enhance signal-to-noise ratio and reduce noise from other directions, while maintaining an open-ear configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If open-ear configuration is used, then user comfort and acceptance are improved, but noise reduction capability deteriorates

Engineering Contradiction:
Improveuser comfort and acceptanceVSAvoidnoise reduction capability
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The device segments the audio processing function into multiple directional channels using an array of microphones. Each microphone captures audio from different spatial directions, allowing the system to separately process and enhance desired directional audio while suppressing noise from other directions, thereby achieving effective noise reduction in open-ear configuration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements feedback through the active noise reduction engine that continuously processes microphone array input, generates anti-noise signals, and feeds them back through acoustic transducers. This closed-loop feedback mechanism dynamically reduces ambient noise while maintaining open-ear comfort for the user.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If directional audio capture is implemented, then speech intelligibility is improved, but device complexity increases

Engineering Contradiction:
Improvespeech intelligibilityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The device merges multiple functions into integrated components: the microphone array simultaneously performs directional audio capture and noise identification, the acoustic transducers deliver both amplified directional audio and active noise reduction signals, and the electronics module handles both beamforming and active noise reduction processing, thereby achieving enhanced speech intelligibility without proportionally increasing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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

Improves speech intelligibility and user experience by enhancing signal-to-noise ratio by at least 5 dB, making open-ear devices more acceptable for users, including those without hearing loss, by improving directional audio capture and noise reduction.

Implementation Method 1

an active noise reduction (ANR) engine that includes one or more processing devices. The ANR engine is configured to generate a driver signal for the at least one acoustic transducer, the driver signal having phases that reduce effects of audio captured from at least the second direction

Methodology Applied
Scientific EffectActive noise reduction: Interference

Implementation Method 2

an array of two or more first microphones that captures audio preferentially from a first direction as compared to at least a second direction different from the first direction, wherein the audio captured using the array is processed

Methodology Applied
Scientific EffectBeamforming: Interference

Data Source

PatentEP4010897B1Active noise reduction in open ear directional acoustic devices
Publication Date: 2025.07.02 BOSE CORP
  • EP4010897B1 patent drawingFigure 1A
  • EP4010897B1 patent drawingFigure 1B
  • EP4010897B1 patent drawingFigure 2

AI summary

An acoustic device includes at least one acoustic transducer disposed such that, in a head-worn state, the at least one acoustic transducer is in an open-ear configuration in which an ear canal of a user of the acoustic device is unobstructed. The acoustic device also includes an array of two or more first microphones that captures audio preferentially from a first direction as compared to at least a second direction different from the first direction, wherein the audio captured using the array is processed and played back through the at least one acoustic transducer, and an active noise reduction (ANR) engine that includes one or more processing devices. The ANR engine is configured to generate a driver signal for the at least one acoustic transducer, the driver signal having phases that reduce effects of audio captured from at least the second direction.