Dynamic Microphone Matching for Hearing Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microphone matching techniques fail to maintain the in-situ transfer characteristic in non-free field acoustic surroundings, particularly when the direction of arrival (DOA) of acoustic signals varies, leading to degradation of directionality and localization in hearing devices.
Innovation Solution
A method for matching acoustical to electrical converters that adjusts their transfer characteristics based on the DOA of incoming signals, using a matching time constant significantly shorter than traditional methods, typically within 0-5 seconds, to maintain the in-situ transfer characteristic and adapt to changing acoustic conditions without affecting the head-related transfer function (HRTF).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional microphone matching techniques are used, then the matching process is simple, but the in-situ transfer characteristic is not maintained when DOA varies
Solution Approach 1:
The patent implements dynamic microphone matching by continuously monitoring the DOA of acoustic signals and adjusting the transfer characteristics of microphones in real-time. The system transitions from static matching to dynamic adaptation, where matching parameters are updated based on current acoustic conditions, enabling the system to maintain optimal performance as DOA changes.
Solution Approach 2:
The patent employs feedback mechanisms where the actual transfer characteristic is compared with the desired transfer characteristic, and adjustment signals are generated to correct deviations. This closed-loop feedback system continuously monitors performance and automatically adjusts microphone characteristics to maintain the in-situ transfer characteristic under varying DOA conditions.
2Speed
If a short matching time constant is used, then the system adapts quickly to changing acoustic conditions, but stability of the matched state is reduced
Solution Approach 1:
The patent implements periodic evaluation and adjustment of microphone matching parameters. Instead of continuous or single-shot matching, the system performs matching at periodic intervals based on detected DOA changes. This periodic action allows the system to adapt quickly to changes while maintaining stability during steady-state conditions, as adjustments are made systematically rather than continuously.
Solution Approach 2:
The patent dynamically changes matching parameters such as gain, phase, and frequency response characteristics based on the detected DOA. By adjusting these parameters in response to acoustic conditions, the system achieves quick adaptation to changing environments while maintaining stable performance through controlled parameter modification rather than random adjustments.
3Measurement precision
If converters are matched for specific DOA ranges, then directionality is improved, but adaptability to varying acoustic environments is reduced
Solution Approach 1:
The patent implements dynamic matching where the system automatically adjusts converter characteristics based on real-time DOA detection. Rather than being fixed for specific DOA ranges, the matching parameters dynamically adapt to the current acoustic environment, enabling the system to maintain high directionality precision across varying conditions while preserving versatility.
Solution Approach 2:
The patent creates a universal matching system that can handle multiple DOA ranges and acoustic environments through a single adaptive framework. The system universally applies matching techniques across different scenarios by detecting the current DOA and adjusting parameters accordingly, making the system versatile for various acoustic conditions without requiring separate specialized matching for each environment.
Data Source
AI summary
Signals dependent on the electrical output signals of two acoustical to electrical converters are computed to result in a result signal. A transfer characteristic between an acoustical signal impinging on the converters and the result signal is dependent on the arrival direction of the acoustical signals at the converters. The converters are matched for acoustical signals within a range of impinging arrival direction. The range of arrival directions is determined before matching.