Hearing Device Lateral Signal Detection via Direction-Dependent Notch Filter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hearing systems struggle to accurately differentiate between central and lateral useful signal sources, particularly in complex hearing situations involving multiple conversation partners, leading to suboptimal signal processing and output.
Innovation Solution
A method utilizing a direction-dependent notch filter unit to compare damping effects between a suspected lateral useful signal source and diffuse background noise, determining the presence or absence of a lateral useful signal source by calculating a measure of attenuation and comparing it to a reference, allowing for adaptive signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hearing systems use conventional signal processing methods to handle multiple conversation partners, then the system can process general ambient sound, but it cannot accurately differentiate between central and lateral useful signal sources
Solution Approach 1:
The patent segments the spatial audio environment by using direction-dependent notch filters to isolate and analyze signals from specific lateral directions separately from the central signal source. This segmentation allows the system to individually process and identify multiple conversation partners based on their spatial positions, resolving the contradiction between measurement precision and adaptability.
Solution Approach 2:
The patent introduces an intermediary comparison mechanism that evaluates the damping effect of the notch filter on lateral signals versus its effect on diffuse background noise. By comparing these two effects, the system can indirectly detect the presence of lateral useful signal sources without directly analyzing their content, thereby improving source differentiation accuracy while maintaining versatility in various listening situations.
2Measurement precision
If hearing systems apply direction-dependent notch filtering to detect lateral signal sources, then signal processing accuracy improves, but system complexity increases
Solution Approach 1:
The patent extracts only the essential characteristic needed for detection - the damping effect comparison between lateral signals and diffuse noise - rather than implementing complex full-spectrum analysis. By taking out and focusing on this specific comparative metric, the system achieves high detection accuracy while avoiding the need for overly complex processing algorithms.
Solution Approach 2:
The patent changes the parameter being measured from direct signal amplitude or spectral content to the comparative damping effect introduced by the notch filter. This parameter transformation simplifies the detection process by converting a complex source identification problem into a simpler comparison of filter-induced attenuation, thereby reducing algorithmic complexity while maintaining high measurement precision.
3Reliability
If hearing systems monitor environment for lateral signal source activity continuously, then detection reliability improves, but energy consumption increases
Solution Approach 1:
The patent implements periodic monitoring through alternating processing modes - continuously monitoring the central signal source while periodically evaluating lateral directions only when central signal quality degrades or at scheduled intervals. This periodic action maintains reliable detection capability while significantly reducing average power consumption compared to continuous omnidirectional monitoring.
Solution Approach 2:
The system uses the central signal processing pipeline to partially serve the lateral detection function by reusing existing signal paths and processing resources. The notch filter and comparison mechanism are designed to leverage already-available signal data, allowing the system to detect lateral sources using minimal additional energy while maintaining high detection reliability.
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a method for operating a hearing system (2) comprising a first input transducer (10), a second input transducer (16), and a signal processing device (14), wherein the activity of a lateral signal source (24) in the vicinity of the hearing system (2) is determined by generating a first input signal (ES1) from an acoustic signal (AS) incident on the first input transducer (10) and a second input signal (ES2) from the acoustic signal (AS) incident on the second input transducer (16), by generating a filtered input signal (GS) based on the first input signal (ES1) and the second input signal (ES2) using a direction-dependent notch filter unit (40), and by determining a measure (M) for attenuation based on the filtered input signal (GS) and based on the first input signal (ES1) and/or the second input signal (ES2).which is caused by the direction-dependent notch filter unit (40) and by comparing the measure (M) to a reference (R), whereby the presence or absence of the activity of a lateral useful signal source (24) in the environment is inferred from the comparison.