In-Car Speech Audio Control for Adaptive Noise Suppression

Solution Overview

Problem

Existing in-car communication systems fail to adequately suppress noise, leading to either imperceptible noise or speech degradation, depending on the ambient noise levels, which negatively impacts user experience.

Innovation Solution

A sound collection loudspeaker apparatus that dynamically adjusts noise suppression based on noise levels at both the microphone and speaker sides, using noise level estimating and suppression amount setting parts to ensure minimal noise perception while maintaining speech quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If noise suppression amount is increased to reduce noise output from speaker, then noise perception is reduced, but speech degradation occurs

Engineering Contradiction:

Improvenoise perceptionVSAvoidspeech quality

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The noise suppression amount is dynamically adjusted based on real-time ambient noise level detection. The system continuously monitors ambient noise and adapts the suppression strength accordingly, transitioning from static to dynamic control to optimize both noise reduction and speech quality preservation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the noise suppression parameter (suppression amount) based on the detected ambient noise level. When ambient noise is high, stronger suppression is applied; when ambient noise is low, weaker suppression is applied, thereby adapting the processing parameters to environmental conditions

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If noise suppression amount is decreased to preserve speech quality, then speech degradation is reduced, but noise output from speaker becomes perceptible

Engineering Contradiction:

Improvespeech qualityVSAvoidnoise perception

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The noise suppression amount is dynamically adjusted based on real-time ambient noise level detection. The system continuously monitors ambient noise and adapts the suppression strength accordingly, transitioning from static to dynamic control to optimize both noise reduction and speech quality preservation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the noise suppression parameter (suppression amount) based on the detected ambient noise level. When ambient noise is high, stronger suppression is applied; when ambient noise is low, weaker suppression is applied, thereby adapting the processing parameters to environmental conditions

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If fixed noise suppression amount is used, then system complexity is reduced, but adaptability to varying ambient noise conditions is lost

Engineering Contradiction:

Improvesystem complexityVSAvoidadaptability to ambient noise

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The system incorporates ambient noise level detection as feedback to continuously monitor environmental conditions. This feedback mechanism enables the system to automatically adjust noise suppression settings based on actual ambient noise levels, achieving adaptability without requiring complex manual configuration

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of noise suppression parameters based on its own ambient noise detection capabilities. The apparatus serves itself by automatically adapting to environmental conditions without external intervention, balancing complexity and adaptability through autonomous operation

Inventive Principle:

Principle #25Self-service

Data Source

PatentEP3813384B1Sound collection/loudspeaker device, method therefor, and program

Publication Date: 2023.09.06 NIPPON TELEGRAPH & TELEPHONE CORP

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AI summary

A first noise level, which is an estimated value of a magnitude of a noise component included in a first sound collection signal obtained from a first microphone which collects sound emitted from a first sound collection and amplification position is obtained, a second noise level, which is an estimated value of a magnitude of a noise component included in a second sound collection signal obtained from a second microphone which collects sound emitted from a second sound collection and amplification position is obtained, a ratio of a reproduced noisy sound level, which is an estimated value of a magnitude of noise at a position of a passenger at the second sound collection and amplification position in a case where the first noise level is reproduced from a second speaker placed at the second sound collection and amplification position, with respect to a second noisy sound level, which is an estimated value of a magnitude of noise corresponding to the second noise level at the position of the passenger at the second sound collection and amplification position is obtained, and a noise suppression amount is obtained so that a product of this ratio and the noise suppression amount becomes a constant set in advance.