Hearing Aid Frequency-Dependent Beamforming
Solution Overview
Problem
Hearing aids with manual or automatic switching between directional and omni-directional modes often eliminate important sound information, leading to inconvenient user experiences and suboptimal noise suppression, especially for hearing-impaired individuals with frequency-dependent hearing loss.
Innovation Solution
A hearing aid system that performs directional processing in a higher frequency range and omni-directional processing in a lower frequency range, with an adjustable lower cutoff frequency to preserve low-frequency localization cues and enhance signal-to-noise ratio, while allowing for user input adjustments based on individual hearing loss or ambient conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If directional processing is applied to improve signal-to-noise ratio, then noise suppression is enhanced, but low-frequency localization cues are lost
Solution Approach 1:
The patent divides the audio signal processing into different frequency bands, applying directional processing only to high-frequency components while preserving low-frequency components in omnidirectional mode. This segmentation allows selective application of noise suppression techniques to specific frequency ranges where they are most beneficial, while maintaining spatial information in frequencies critical for localization.
Solution Approach 2:
The patent applies different processing qualities to different frequency regions: directional processing with enhanced noise suppression is applied to high frequencies, while omnidirectional processing with preserved spatial cues is applied to low frequencies. This local quality differentiation optimizes both noise suppression and localization performance by matching processing characteristics to the specific needs of each frequency band.
2Ease of operation
If manual switching between directional and omnidirectional modes is implemented, then user control over processing mode is provided, but user convenience deteriorates due to frequent mode changes
Solution Approach 1:
The patent implements dynamic, automatic switching between directional and omnidirectional processing modes based on real-time analysis of listening conditions, eliminating the need for manual user intervention. The system automatically adapts its processing characteristics to match the current acoustic environment, providing both user control and convenience simultaneously.
Solution Approach 2:
The hearing aid system performs self-service by automatically detecting listening conditions and selecting the appropriate processing mode without requiring user input. The device monitors acoustic parameters and autonomously switches between processing modes, freeing the user from the burden of manual mode selection while maintaining optimal performance.
3Loss of information
If omnidirectional processing is used to preserve access to all sound sources, then spatial awareness is improved, but signal-to-noise ratio deteriorates in noisy environments
Solution Approach 1:
The patent segments the frequency spectrum into low and high frequency bands, applying omnidirectional processing to low frequencies to preserve spatial information while applying directional processing to high frequencies to improve signal-to-noise ratio. This frequency-based segmentation allows simultaneous optimization of both spatial awareness and noise rejection.
Solution Approach 2:
The patent applies different processing qualities to different frequency regions: omnidirectional processing is applied to low frequencies where spatial cues are most important, while directional processing is applied to high frequencies where noise suppression provides greater benefit. This local differentiation of processing quality resolves the contradiction between spatial awareness and signal-to-noise ratio.
Data Source
AI summary
A hearing aid includes a first microphone for providing a first audio input signal, a second microphone for providing a second audio input signal, a signal processor configured for generating a hearing loss compensated audio output signal based at least in part on the audio input signals, and a receiver for converting the audio output signal into an output sound signal, wherein the signal processor is configured to perform directional processing, based on the first and second audio input signals, in a first frequency range and substantially omni-directional processing in a second frequency range, at least a part of the first frequency range being higher than the second frequency range, and wherein a lower cutoff frequency of the first frequency range is adjustable.