Audio Device Attenuators for Speech Intelligibility

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Solution Overview

Problem

Existing audio devices face challenges in maintaining equal microphone sensitivity across frequency ranges due to production tolerances and aging, handling multiple noise types, and stabilizing beamforming with multiple beamformers, which affect audio quality and intelligibility.

Innovation Solution

An audio device with a processor that processes signals from multiple microphones using beamforming, attenuators, and noise suppression schemes to enhance speech quality and intelligibility by applying primary and secondary gains based on microphone features, combining them into a compensated gain, and applying a noise suppression scheme.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If beamforming with multiple beamformers is used to improve audio quality and noise suppression, then speech intelligibility is improved, but computational load increases and stability decreases

Engineering Contradiction:
Improvespeech intelligibilityVSAvoidcomputational load
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the beamforming process into multiple sequential stages: first beamforming to obtain preliminary beamformed signals, then second beamforming to further suppress noise. This segmentation allows complex noise suppression to be achieved through simpler, sequential operations rather than a single complex beamforming process, reducing overall computational load while maintaining speech intelligibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary beamforming processing to obtain initial beamformed signals before applying the second beamforming stage. This preliminary action prepares the signals in advance, making the subsequent noise suppression more efficient and reducing the computational complexity of the final processing stage.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If multiple beamformers are used to handle different noise types, then noise suppression capability is improved, but system stability deteriorates

Engineering Contradiction:
Improvenoise suppression capabilityVSAvoidsystem stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent employs adaptive beamforming where the beamforming parameters and weights are dynamically adjusted based on the estimated noise characteristics in different time-frequency regions. This dynamic adaptation allows the system to handle different noise types effectively while maintaining stability through continuous optimization rather than fixed complex multi-beamformer configurations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes beamforming parameters (weights, coefficients) based on noise type detection and estimation. By adjusting parameters dynamically according to the acoustic environment, the system achieves versatile noise suppression capability while maintaining stability through parameter optimization rather than structural complexity.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If production tolerances and component variations are accepted to reduce manufacturing cost, then manufacturing ease is improved, but microphone sensitivity equality deteriorates

Engineering Contradiction:
Improvemanufacturing costVSAvoidmicrophone sensitivity equality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent measures the actual sensitivity characteristics of each microphone during or after assembly, then uses this feedback information to compute compensation weights for the beamforming process. This feedback mechanism allows the system to achieve equal effective sensitivity despite manufacturing variations, eliminating the need for tight production tolerances while maintaining audio quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent adjusts the beamforming weights and coefficients based on measured microphone characteristics to compensate for sensitivity variations. By changing the processing parameters rather than requiring precise manufacturing, the system achieves equal effective sensitivity at lower manufacturing cost.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4156183B1Audio device with a plurality of attenuators
Publication Date: 2025.10.22 GN HEARING AS
  • EP4156183B1 patent drawingFigure 1
  • EP4156183B1 patent drawingFigure 2
  • EP4156183B1 patent drawingFigure 3

AI summary

An audio device comprising an interface, memory, and a processor is disclosed, wherein the processor is configured to: obtain a first microphone input signal and a second microphone input signal; process the first microphone input signal and the second microphone input signal for provision of an output audio signal; and output the output audio signal; wherein to process the first microphone input signal and the second microphone input signal comprises to: determine a primary gain with a primary attenuator based on one or more features associated with the first microphone input signal and the second microphone input signal; determine a secondary gain with a secondary attenuator based on one or more features associated with the first microphone input signal and the second microphone input signal; determine a noise suppression scheme based on the primary gain and the secondary gain; and apply the noise suppression scheme to a first beamforming output signal for provision of the output audio signal.