Binaural Hearing System Externalizing Sound Sources
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Binaural hearing systems struggle to effectively separate and localize multiple sound sources, leading to listening fatigue and difficulty in understanding speech in noisy environments due to internalized sound reproduction.
Innovation Solution
A binaural hearing system that adds spatial cues to electronic monaural signals by using directional transfer functions and binaural filters to simulate the Head Related Transfer Function (HRTF), allowing users to perceive sound sources as externalized and improving sound source segregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional binaural hearing systems reproduce sound internally, then the user perceives sound sources inside the head, but this causes listening fatigue and difficulty in separating multiple sound sources
Solution Approach 1:
The patent uses an intermediary processing stage that analyzes the acoustic environment and applies appropriate transfer functions to externalize sound sources. The system introduces a mediating computational layer that processes binaural signals to add spatial cues, allowing sound sources to be perceived externally rather than internally. This intermediary processing resolves the contradiction by transforming the internalized sound field into an externalized one that facilitates source separation.
Solution Approach 2:
The system dynamically changes parameters of the transfer functions applied to different frequency bands and spatial locations. By adjusting the parameters of HRTF filters based on the estimated direction of arrival and acoustic environment, the system can adaptively externalize sound sources while maintaining internalization when appropriate. This parameter adaptation resolves the contradiction by providing flexible control over sound localization characteristics.
2Adaptability or versatility
If the system processes multiple electronic monaural signals simultaneously, then more sound sources can be received, but the user finds it difficult to separate one signal source from another
Solution Approach 1:
The patent segments the processing of multiple sound sources by applying distinct transfer functions to each signal based on its estimated spatial location. Each monaural signal is processed independently through dedicated HRTF filters corresponding to its direction of arrival, creating separate spatial channels. This segmentation preserves spatial separation information even when multiple signals are processed simultaneously, resolving the contradiction between multi-signal reception and source separation.
Solution Approach 2:
The system adds the spatial dimension to monaural signals by applying directional transfer functions that encode azimuth and elevation information. By transforming one-dimensional monaural signals into three-dimensional spatially-encoded binaural signals, the system enables users to separate multiple sound sources based on their spatial positions, resolving the loss of spatial separation information when processing multiple signals.
3Measurement precision
If directional transfer functions and binaural filters are applied to externalize sound sources, then sound source segregation is improved, but the processing complexity increases
Solution Approach 1:
The patent applies partial externalization by selectively processing only certain frequency bands or certain sound sources with full HRTF filtering, while leaving others with minimal processing. This partial action approach achieves sufficient sound source segregation for critical signals without applying excessive processing complexity to all signals uniformly, resolving the contradiction between localization precision and processing complexity.
Solution Approach 2:
The system dynamically adjusts the application of transfer functions based on real-time estimation of sound source positions and acoustic conditions. The processing complexity is modulated dynamically - applying full HRTF filtering when externalization is needed for source separation, and reducing processing when sources are already well-separated. This dynamic adaptation resolves the contradiction by optimizing the balance between localization precision and processing complexity based on current listening conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances the user's ability to separate and focus on specific sound sources, improving speech understanding in noisy environments by externalizing sound sources and reducing cognitive loading.
Implementation Method 1
A binaural hearing system that adds spatial cues to electronic monaural signals by using directional transfer functions and binaural filters to simulate the Head Related Transfer Function (HRTF)
Data Source
AI summary
A new hearing aid is provided in which signals that are received from an external device, such as a spouse microphone, a media player, a hearing loop system, a teleconference system, a radio, a TV, a telephone, a device with an alarm, etc., are filtered in such a way that a user can localize the monaural signal transmitter.