Hearing Device Comb Filter Suppression
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Solution Overview
Problem
Hearing devices, particularly those with open fittings, suffer from comb filtering effects, which degrade the listening experience, and traditional methods fail to effectively address this issue.
Innovation Solution
A hearing device comprising an input module, processor, suppressor, and receiver, where the suppressor applies a delay and filter with specific gain settings to reduce comb filtering, utilizing a comb suppressor with a primary suppressor part and a suppressor controller to control the delay and filter based on input signals and processor outputs, thereby improving audio output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an open fitting is used in a hearing device, then comfort and natural sound perception are improved, but comb filtering effects occur that degrade the listening experience
Solution Approach 1:
The patent applies preliminary anti-action by generating an anti-comb filter signal that precedes and counteracts the comb filtering effects. The suppressor creates a compensating signal with opposite phase characteristics to cancel out the harmful comb filtering that would otherwise occur in the open fitting hearing device, thereby maintaining both comfort and sound quality.
Solution Approach 2:
The patent introduces an intermediary suppressor component that mediates between the audio signal path and the output. This suppressor processes the audio signal to generate a modified signal that eliminates comb filtering effects while preserving the natural sound characteristics that users benefit from, acting as a mediator that reconciles the contradiction between open fitting benefits and comb filtering problems.
2Device complexity
If traditional signal processing methods are used, then device complexity is kept low, but comb filtering effects are not effectively suppressed
Solution Approach 1:
The patent applies segmentation by dividing the signal processing into distinct functional segments: the original audio signal path and the separate suppressor path. The suppressor is further segmented into specific processing stages including delay elements, filtering stages, and signal combination points. This segmented approach enables effective comb filtering suppression while maintaining manageable device complexity through modular processing architecture.
3Object-affected harmful factors
If suppression is applied continuously, then comb filtering is reduced, but power consumption increases
Solution Approach 1:
The patent implements periodic action by enabling the suppressor to operate selectively rather than continuously. The suppressor can be activated during specific time periods when comb filtering effects are detected or expected to occur, and deactivated during periods when they are not present. This periodic operation maintains effective comb filtering suppression while significantly reducing overall power consumption compared to continuous suppression.
Data Source
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AI summary
A hearing device includes: an input module for provision of a first input signal, the input module comprising a first microphone; a processor for provision of a processor output signal based on the first input signal; a suppressor for provision of a first suppressor output signal based on one or more suppressor input signals including a first suppressor input signal; a first adder coupled to the suppressor, the first adder configured for provision of a first adder output signal based on at least a part of the processor output signal and the first suppressor output signal; and a receiver for converting an output signal based on the first adder output signal to an audio output signal; wherein the suppressor is configured to apply a first delay and a first filter with a first gain to at least a part of the first suppressor input signal.