In-Car Audio Feedback Control via Adaptive Gain
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Solution Overview
Problem
In-vehicle communication systems face challenges in noisy environments due to noise interference, which can lead to feedback issues like ringing or howling, making it difficult for drivers and passengers to communicate effectively.
Innovation Solution
The system employs adaptive gain and feedback control mechanisms to dynamically adjust the signal processing, using microphone and loudspeaker pairs to minimize feedback by controlling the closed-loop gain in a frequency-dependent manner, thereby preventing unstable states and ensuring clear communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voice signal levels are increased to overcome noisy environments, then communication clarity is improved, but feedback causing ringing or howling occurs
Solution Approach 1:
The system uses feedback control mechanisms where the output signal is continuously monitored and fed back to the input stage. An adaptive filter processes the feedback signal to generate cancellation signals that subtract from the original signal, thereby reducing feedback-induced ringing and howling while preserving clear communication.
Solution Approach 2:
The patent introduces an intermediary feedback control system between the audio output and input stages. This intermediary processes the audio signal through adaptive filtering and generates cancellation signals that mediate the interaction between loudspeaker output and microphone input, preventing direct feedback loops that cause ringing.
2Stability of the object's composition
If feedback control is implemented to prevent ringing, then feedback stability is improved, but communication clarity may deteriorate
Solution Approach 1:
The system employs dynamic adaptive filtering where the filter coefficients continuously adjust based on real-time analysis of the audio signal and feedback characteristics. This dynamic adaptation allows the system to maintain feedback stability while preserving communication clarity by optimizing the cancellation signals for current operating conditions.
Solution Approach 2:
The patent changes key parameters of the feedback control system including adaptive filter coefficients, gain levels, and frequency response characteristics. These parameter changes are dynamically adjusted based on signal analysis to maintain stability while preserving audio quality and communication clarity.
Data Source
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AI summary
A system and method (referred to as the system) that mitigates feedback in an audio system that adjust voice signals in a vehicle. The system generates transfer function estimates from multiple loudspeakers to multiple microphones and generates maximum forward path frequency-dependent gains based on the transfer function estimates and a frequency-dependent tuning factor for each of the loudspeakers to each of the microphones. The system generates forward path frequency-dependent gains independently that are applied to multiple loudspeaker signals, each of the loudspeaker signals drive one of the loudspeakers, respectively. The forward path frequency-dependent gains are adjusted based on the maximum forward path frequency-dependent gains.