Binaural Hearing Aid Signal Alignment for Noise Suppression
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Solution Overview
Problem
Binaural hearing aid systems face challenges in effectively suppressing background noise due to differing signal recordings from multiple microphones, leading to poor noise suppression and additional acoustic artifacts, especially with adaptive methods that converge slowly or not at all.
Innovation Solution
A method for a hearing aid system that filters audio signals with a predetermined filter to align useful signal components, followed by an adaptive filter to further match these components, allowing for faster convergence and improved noise suppression with reduced computing power and memory requirements, and enabling better reference signals for interference noise cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adaptive noise suppression methods are used in binaural hearing aid systems, then noise suppression performance can be improved, but the convergence speed is very slow or does not converge at all due to significant differences in useful signals recorded by microphones on different hearing aid devices
Solution Approach 1:
The patent applies preliminary action by introducing a predetermined filter before the adaptive filter to pre-align the useful signal components in the audio signals from different hearing aid devices. This preliminary filtering step matches the useful signal components to a greater extent before the adaptive filter processes the signals, enabling the adaptive filter to converge faster and achieve better noise suppression performance.
2Reliability
If adaptive filters with longer lengths are used to improve noise suppression, then suppression effectiveness increases, but computing power requirements and memory requirements increase
Solution Approach 1:
The predetermined filter performs preliminary alignment of useful signal components, which allows the subsequent adaptive filter to achieve the same noise suppression effectiveness with a shorter filter length. This reduces the number of coefficients that need to be computed and stored, thereby reducing computing power and memory requirements.
3Measurement precision
If multiple microphones are used to record audio signals in binaural hearing aid systems, then spatial audio capture is improved, but the useful signals recorded by different microphones differ significantly due to reverberation and acoustic influence of the wearer's head
Solution Approach 1:
The predetermined filter acts as an intermediary that processes the audio signals from different microphones to align the useful signal components. It compensates for the differences caused by reverberation and acoustic influence of the wearer's head, enabling better signal alignment for subsequent noise suppression processing.
Data Source
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AI summary
The invention relates to a method for operating a hearing aid system (100) and to a hearing aid system (100) comprising at least two hearing aids (110, 110') between which a signal path is provided, and at least one signal processing unit (3, 3') designed for processing audio signals. In the method according to the invention, the signal processing device (3, 3') filters first audio signals with a filter (31, 31') predetermined for a given spatial direction from which a useful signal arrives, so that second audio signals are generated in which the components of the useful signal in the second audio signals are more closely matched than in the first audio signals. Subsequently, the second audio signals are filtered with an adaptive filter (32, 32') so that third audio signals are generated in which the components of the useful signal are even more closely matched than in the second audio signals.