Microphone Array Gain Matching for Capsule Sensitivity Drift
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Solution Overview
Problem
Microphone arrays in vehicles face challenges due to sound wave exposure variance and noise, particularly from wind, leading to sensitivity mismatches among capsules, which affect directivity and noise reduction capabilities.
Innovation Solution
A method and system for blind sensitivity matching of microphone capsules in an array, adjusting gain values based on average error calculations to minimize sensitivity mismatches, using a processor to determine and adjust gain steps for each capsule.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If microphone capsules are arranged in a microphone array for sound detection, then speech detection capability is improved, but sensitivity mismatch and noise interference increase due to sound wave exposure variance
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the gain values of individual microphone capsules based on calculated sensitivity errors. The system computes an average error value from raw sound exposure amplitude values and adjusts each capsule's gain parameter to compensate for sensitivity mismatches, thereby maintaining consistent sensitivity across the array while preserving speech detection capability
Solution Approach 2:
The patent implements feedback through a continuous sensitivity matching process. The system monitors raw sound exposure amplitude values from each capsule, calculates average error values, and uses this feedback to iteratively adjust gain parameters. This closed-loop feedback mechanism ensures that sensitivity inconsistencies are detected and corrected in real-time, improving both measurement precision and reliability
2Reliability
If gain adjustment is applied to correct sensitivity mismatch, then sensitivity consistency is improved, but system complexity increases due to additional processing steps
Solution Approach 1:
The patent applies self-service by enabling the microphone array system to automatically perform sensitivity matching without external intervention. The system autonomously calculates average error values from its own raw sound exposure measurements, determines appropriate gain adjustments, and applies corrections internally. This self-service approach improves sensitivity consistency while minimizing the need for additional external processing equipment
Solution Approach 2:
The patent implements preliminary action by performing sensitivity matching calculations and gain adjustments during the signal processing stage before final audio output. By pre-calculating average error values and applying gain corrections in advance, the system ensures sensitivity consistency is established prior to noise reduction and speech detection processing, thereby managing complexity through structured preprocessing
3Object-affected harmful factors
If average error calculation is performed for sensitivity matching, then noise reduction capability is improved, but processing time increases
Solution Approach 1:
The patent applies partial action by calculating average error values selectively based on the minimum number of microphone capsules required for accurate sensitivity matching. Rather than processing data from all capsules equally, the system determines sufficient sampling points and uses only those necessary for reliable average error calculation. This approach reduces processing time while maintaining effective noise reduction capability through targeted sensitivity correction
Data Source
AI summary
A method for sensitivity matching of microphone capsules in a microphone array includes: determining, for at least two microphone capsules in a microphone array, an average raw sound exposure amplitude value; calculating an average error value for the at least two microphone capsules based on the average raw sound exposure amplitude value and respective sensitivity-adjusted exposure values for each microphone capsule of the at least two microphone capsules; determining, based on the average error value, a first gain step value for at least one microphone capsule of the at least two microphone capsules; determining, based on a minimum gain value and a maximum gain value, a second gain step value for each microphone capsule of the at least one microphone capsule of the at least two microphone capsules; and adjusting a gain of the at least one microphone capsule based on the second gain step value.