Hearing Aid Frequency Distortion for Latency and Artifact Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for suppressing acoustic feedback in hearing aids often introduce latency and artifacts due to the use of high-pass and low-pass filters for frequency distortion, which are not optimized for minimizing latency and artifact suppression.
Innovation Solution
The method involves dividing the audio signal into multiple frequency bands using a filter bank, determining a target frequency for frequency distortion based on acoustic feedback, and applying different frequency distortions to adjacent bands, with specific amplification and filtering to minimize latency and artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-pass and low-pass filters are used to divide frequency ranges for frequency distortion, then acoustic feedback suppression is achieved, but latency is introduced into the acoustic system
Solution Approach 1:
The audio signal is divided into multiple frequency bands using a filter bank, where each band can be independently processed. This segmentation allows frequency distortion to be applied selectively to specific bands that contain feedback, avoiding the need for broad high-pass/low-pass filtering that introduces latency across the entire signal path.
Solution Approach 2:
Different frequency distortion parameters are applied to different frequency bands based on local characteristics. The target frequency for frequency distortion is determined specifically for each band containing acoustic feedback, allowing optimized processing that minimizes latency while maintaining effective feedback suppression in the affected frequency ranges.
2Reliability
If frequency distortion is applied to suppress acoustic feedback, then feedback suppression effectiveness is improved, but artifacts are generated in the output signal
Solution Approach 1:
Frequency distortion is applied partially—only to the specific frequency band containing the target frequency that corresponds to acoustic feedback. By limiting the distortion application to only the necessary frequency range rather than applying it broadly, the effectiveness of feedback suppression is maintained while minimizing the generation of artifacts in other frequency bands.
Solution Approach 2:
The frequency distortion parameters (such as the target frequency and distortion amount) are dynamically adjusted based on the detected acoustic feedback characteristics in each frequency band. This adaptive parameter change allows the system to maintain effective feedback suppression while reducing artifacts by optimizing distortion application to match the actual feedback conditions.
3Object-generated harmful factors
If the division frequency is adapted to minimize artifacts, then artifact suppression is improved, but device complexity increases due to additional filtering operations
Solution Approach 1:
The filter bank serves multiple functions simultaneously: it divides the audio signal into frequency bands for selective processing, determines the target frequency for frequency distortion, and enables artifact suppression through its frequency-selective structure. This multi-functionality reduces the need for additional dedicated filtering operations, thereby limiting device complexity while achieving effective artifact suppression.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention describes a method (40) for frequency distortion (22) of an audio signal (42), wherein the audio signal (42) is divided into a plurality of predetermined frequency bands (FB, FB1, FB2, FB3), wherein a band cutoff frequency (fL0-fL3) is determined by each pair of immediately adjacent frequency bands (FB1, FB2, FB3), wherein a first frequency band (FB1) and a second frequency band (FB2) lying directly above the first frequency band (FB1) are determined on the basis of the audio signal (42), and wherein a different distortion (22) of the frequencies is applied to signal components (44) in the first frequency band (FB1) than to signal components (44) in the second frequency band (FB2), thereby generating a frequency-distorted signal (24).