In-Car End-Fire Microphone Array for Noise and Echo Cancellation
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Solution Overview
Problem
Existing audio systems in vehicles fail to effectively separate voice signals from background noises and cancel echoes in reverberant environments, compromising the signal-to-noise ratio and overall audio quality during hands-free calls and voice recognition.
Innovation Solution
An array of microphones in an end-fire configuration, combined with a dual-mode digital signal processor, employs beamforming modules for noise and echo cancellation, and adaptive noise cancellation modules to enhance audio processing in noisy and reverberant vehicle interiors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional microphones are used in vehicle audio systems, then the device complexity is low, but the signal-to-noise ratio deteriorates due to inability to separate voice signals from background noises
Solution Approach 1:
The audio system segments the microphone array into multiple individual microphone elements arranged in specific geometric patterns (end-fire, broadside, V-shaped configurations). Each microphone element captures audio signals independently, allowing the system to process and separate different sound sources through spatial filtering and beamforming techniques, thereby improving signal-to-noise ratio in noisy vehicle environments.
2Reliability
If conventional single-microphone systems are used, then the device complexity is low, but the echo cancellation capability is insufficient in reverberant vehicle environments
Solution Approach 1:
The patent introduces digital signal processing algorithms as intermediaries that mediate between the multiple microphone inputs and the final audio output. These algorithms include beamforming modules that steer acoustic beams toward desired sound sources and adaptive noise cancellation modules that filter out reverberations and echoes, enabling effective echo cancellation in vehicle environments without requiring complex hardware modifications.
3Reliability
If simple microphone arrangements are used, then the ease of manufacture is high, but the audio clarity deteriorates in noisy and reverberant environments
Solution Approach 1:
The system dynamically changes processing parameters including beamforming weights, noise cancellation coefficients, and signal filtering characteristics based on real-time acoustic environment analysis. By adapting these parameters to match the specific noise and reverberation conditions in vehicle environments, the system maintains high audio clarity without requiring overly complex fixed-configuration hardware.
Data Source
AI summary
The present application discloses exemplary arrangements of an end-fire microphone array inside a vehicle and exemplary digital signal processors configured for the end-fire in-car microphone array. The exemplary digital signal processors may be configured in two modes, a phone call mode and an automatic speech recognition mode. In each mode, the exemplary digital signal processors are improved for enhanced SNR. Different end-fire microphone array arrangements are also disclosed.