Three-Sensor Audio Mixing for Voice Noise Mitigation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing audio systems using both air conduction and bone conduction sensors fail to effectively mitigate noise in noisy environments, as they either introduce ambient noise or muffle the voice signal, and existing mixing schemes are inadequate for varying environmental conditions.

Innovation Solution

A method and system that combines audio signals from at least three sensors - a bone conduction sensor, an internal air conduction sensor, and an external air conduction sensor - using defined crossing frequencies to optimize noise mitigation across different frequency bands, with adaptive or static frequency adjustments based on operating conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If only the air-conducted signal is used in the output signal, then the spectral bandwidth is sufficient, but the output signal contains more ambient noise

Engineering Contradiction:
Improvespectral bandwidthVSAvoidambient noise
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent combines the air-conducted signal and bone-conducted signal through adaptive mixing to create an output signal that maintains sufficient spectral bandwidth while reducing ambient noise. The mixing process merges the complementary strengths of both sensor types to resolve the contradiction between information preservation and noise reduction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs adaptive mixing schemes that dynamically adjust the contribution of each sensor signal based on real-time environmental conditions. This dynamic adaptation allows the system to optimize the balance between spectral bandwidth and noise reduction according to varying acoustic scenarios.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If only the bone-conducted signal is used in the output signal, then ambient noise is reduced, but the voice signal becomes strongly low-pass filtered causing muffled sound

Engineering Contradiction:
Improveambient noiseVSAvoidvoice intelligibility
Core Design Contradiction:
Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The patent merges the bone-conducted signal with the air-conducted signal to compensate for the low-pass filtering effect. The combination restores the high-frequency components necessary for voice intelligibility while maintaining the noise reduction benefits of bone conduction through adaptive weighting.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the mixing parameters adaptively based on environmental conditions, adjusting the proportion of bone-conducted and air-conducted signals to optimize both noise reduction and voice clarity. This parameter adaptation resolves the contradiction between noise reduction and intelligibility preservation.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If a static mixing scheme is used, then the implementation is simple, but the noise mitigation is inadequate for varying environmental conditions

Engineering Contradiction:
Improveimplementation simplicityVSAvoidnoise mitigation adaptability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent transitions from static to dynamic mixing schemes that adapt to varying environmental conditions. The system monitors acoustic characteristics and adjusts mixing parameters in real-time, enabling effective noise mitigation across diverse scenarios while maintaining reasonable implementation complexity through efficient algorithms.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4505452B1Audio signal processing techniques for noise mitigation
Publication Date: 2026.03.11 ANALOG DEVICES INT UNLTD CO
  • EP4505452B1 patent drawingFigure 1~2
  • EP4505452B1 patent drawingFigure 3
  • EP4505452B1 patent drawingFigure 4

AI summary

An audio signal processing method includes measuring a voice signal, wherein the measurement performed by an audio system including first through third sensors. Measuring the voice signal produces first through third audio signals by the first through third sensors, respectively. The audio signal processing method further includes: producing an output signal by using the first audio signal, the second audio signal and the third audio signal, wherein the output signal corresponds to: the first audio signal below a first crossing frequency, the second audio signal between the first crossing frequency and a second crossing frequency, the third audio signal above the second crossing frequency, wherein the first crossing frequency and the second crossing frequency are different for at least some operating conditions of the audio system.