Hearing Device Noise Suppression Using Dual Adaptation Coefficients
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Solution Overview
Problem
Hearing devices face challenges in improving the signal-to-noise ratio (SNR) when dealing with steady background noise and transient wanted signals, as existing direction-dependent signal processing algorithms often incorporate noise into the output signal, affecting speech quality and intelligibility.
Innovation Solution
A method for operating a hearing device that generates two directional signals with different sensitivity patterns, using adaptation coefficients to superimpose them in a way that suppresses steady noise while minimizing the impact of transient signals, by adjusting response times to optimize noise suppression and using a linear combination of adaptation coefficients to form an output signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single adaptation coefficient is used for noise suppression, then the device complexity is reduced, but the ability to differentiate between steady noise and transient wanted signals deteriorates
Solution Approach 1:
The patent divides the single adaptation coefficient into two separate adaptation coefficients (first adaptation coefficient and second adaptation coefficient), each responsible for different aspects of noise suppression. This segmentation allows the system to differentiate between steady noise and transient wanted signals by using different response times for each coefficient, thereby resolving the contradiction between device complexity and adaptability.
2Speed
If the adaptation coefficient varies quickly to suppress transient noise, then the noise suppression speed is improved, but the steady noise is incorrectly modulated affecting speech quality
Solution Approach 1:
The patent introduces different response times for the two adaptation coefficients. The first adaptation coefficient uses a first response time optimized for transient noise suppression, while the second adaptation coefficient uses a second response time optimized for steady noise suppression. This dynamic differentiation allows the system to respond appropriately to different noise types without compromising speech quality.
Solution Approach 2:
The patent changes the response time parameter differently for the two adaptation coefficients. By setting the first response time shorter than the second response time, the system can quickly suppress transient noise while the longer second response time prevents incorrect modulation of steady noise, thereby maintaining speech quality and intelligibility.
3Ease of operation
If a single response time is used for adaptation coefficient determination, then the processing simplicity is maintained, but the optimization for both transient and steady noise is compromised
Solution Approach 1:
The patent segments the single response time parameter into two distinct response times (first response time and second response time), each optimized for different noise characteristics. This segmentation maintains processing simplicity through clear separation of functions while significantly improving the overall optimization effectiveness for both transient and steady noise suppression.
Data Source
AI summary
A method for operating a hearing device. In the hearing device a first directional signal and a second directional signal are generated from an ambient sound signal. The first directional signal and the second directional signal are used to determine at a first response time a first adaptation coefficient for a first superposition of the first directional signal with the second directional signal for the purpose of noise suppression. It is intended here that the first directional signal and the second directional signal are used to determine at a second response time a second adaptation coefficient for a second superposition of the first directional signal with the second directional signal for the purpose of noise suppression. The first adaptation coefficient and the second adaptation coefficient are used to determine an output adaptation coefficient for forming an output signal by superposition of the first directional signal and the second directional signal.