Bimodal Hearing System ILD Cue Preservation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bimodal hearing systems fail to reliably map inter-aural level differences (ILD) to loudness differences due to the use of different types of stimulation and signal processing strategies in each ear, leading to inconsistent loudness across ears, especially with head-shadow effects.
Innovation Solution
A method is implemented to calculate target loudness ratios based on input signals from both hearing prostheses and adjust gain settings to match the inter-aural loudness ratio with the target ratio, ensuring that loudness differences between ears align with ILD cues, using a bidirectional communication channel between a cochlear implant and a hearing aid to exchange necessary data for sound processing adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different types of stimulation and signal processing strategies are used in each ear of a bimodal hearing system, then the system can accommodate different hearing losses and provide personalized hearing enhancement, but the inter-aural loudness ratio becomes inconsistent and ILD cues are not reliably preserved
Solution Approach 1:
The system continuously monitors the inter-aural loudness ratio by comparing loudness measurements from both ears and dynamically adjusts processing parameters to maintain the target ratio, creating a closed-loop feedback mechanism that preserves ILD cues despite different stimulation types
Solution Approach 2:
The system changes processing parameters such as gain, compression ratios, and loudness normalization factors to adjust the inter-aural loudness ratio, allowing the same input signal to produce appropriate loudness differences that preserve ILD cues across different stimulation types
2Reliability
If gain settings are adjusted to match inter-aural loudness ratio, then ILD cues are preserved for sound localization, but the dynamic range utilization in each prosthesis may be suboptimal
Solution Approach 1:
The system dynamically adjusts gain settings and compression parameters in real-time based on the target inter-aural loudness ratio, allowing the processing to adapt to different listening conditions while maintaining ILD cue preservation and optimizing dynamic range utilization
3Reliability
If loudness normalization is applied to compensate for head-shadow effects, then hearing thresholds are improved, but the natural ILD cues are distorted
Solution Approach 1:
The system applies different processing strategies to different ears based on their specific needs - one ear may receive more aggressive loudness normalization to compensate for head-shadow effects while the other ear maintains more natural processing, with the inter-aural ratio adjusted to preserve ILD cues
Data Source
AI summary
Presented herein are techniques to calculate long-term loudness measures for each of the prostheses in a bimodal hearing system and exchange this information across the two sides. The bimodal hearing system operates to ensure that the loudness differences between the two sides follow the ILDs between the two sides. Stated differently, the techniques presented herein determine a target loudness ratio based on the input signals (sound signals) received at each of the first second hearing prostheses in a bimodal hearing system. The techniques presented herein further determine an estimated inter-aural loudness ratio based on output signals that would be generated by each of the first and second hearing prostheses based on the input signals. Operation of either or both of the first or second hearing prostheses is adjusted so as to substantially match the estimated inter-aural loudness ratio to the target loudness ratio.