Binaural Hearing Aid Frequency Unmasking
Solution Overview
Problem
Current digital hearing aids using multi-channel amplification and compression struggle to enhance speech intelligibility in noise environments, as they cannot effectively differentiate between target and masker signals, often removing parts of the audio signal that the listener intends to focus on.
Innovation Solution
A binaural hearing aid system that separates target and masker signals into different frequency bands, utilizing interaural time and level differences to reduce energetic masking, and adjusts the phase of these signals to improve the user's ability to distinguish the target signal from the masker, thereby enhancing speech intelligibility without removing any part of the signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional beamforming or spectral subtraction techniques are used to enhance target signal and remove noise, then speech intelligibility in noise is improved, but parts of the audio signal that the listener is trying to focus on may be removed
Solution Approach 1:
The patent applies frequency transposition specifically to the masker signal, changing its frequency parameter to occupy a different spectral region. This allows the masker to be attenuated after transposition without affecting the original target signal frequencies, thus improving speech intelligibility while preserving the target audio information.
Solution Approach 2:
The patent segments the audio signal into target signal and masker signal components using signal separation techniques. This segmentation allows selective processing where the masker is frequency-transposed and attenuated while the target signal remains intact, resolving the contradiction between noise reduction and information preservation.
2Illumination intensity
If multi-channel amplification and compression is applied to restore audibility, then hearing threshold is compensated, but the ability to understand speech in noise remains poor
Solution Approach 1:
The patent changes the frequency parameter of the masker signal through transposition, shifting it to a different spectral region. When combined with multi-channel amplification, this allows the target signal to be amplified for audibility while the transposed masker occupies separate frequency channels, improving both audibility and speech-in-noise intelligibility.
Solution Approach 2:
The patent moves the masker signal to a different frequency dimension through transposition. This dimensional separation allows independent processing of target and masker signals across different frequency channels, enabling amplification of target signal for audibility while suppressing the transposed masker, thus improving speech-in-noise understanding.
3Measurement precision
If frequency transposition is applied to masker signal, then energetic masking is reduced and speech intelligibility is improved, but device complexity increases
Solution Approach 1:
The patent applies frequency transposition to the masker signal, changing its spectral parameter to reduce masking. This parameter change improves signal-to-noise ratio and speech intelligibility while using established signal processing techniques that can be implemented in digital hearing aid processors.
Solution Approach 2:
The patent replaces complex mechanical or acoustic filtering methods with digital signal processing techniques for frequency transposition. This substitution allows precise control of the transposition process and selective application to masker components, improving SRT while managing device complexity through software-based processing.
Data Source
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AI summary
A new binaural hearing aid system is provided that compensates for a hearing impaired user's loss of ability to understand speech in noise using a new method comprising the steps of providing at least one microphone audio signal (18, 20) in response to sound, and providing an estimate of one of a target signal (26) and a noise signal (30) based on the at least one audio signal (18, 20), frequency modifying at least one of the estimate of the target signal (26) and the estimate of the noise signal (30) in such a way that the estimate of the target signal (26) and the estimate of the noise signal (30) as modified substantially reside in different frequency bands, and transmitting the estimate of the target signal as modified towards one of the eardrums of a user of the binaural hearing aid system (10), and transmitting the estimate of the noise signal as modified towards the other one of the eardrums of the user.