Bilateral Hearing Implant ITD-ILD Coordination
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Solution Overview
Problem
Existing cochlear implant systems fail to effectively utilize interaural time differences (ITDs) for improved sound localization and speech understanding in noisy environments, relying primarily on envelope ITD information and lacking integration of fine structure ITD information.
Innovation Solution
A bilateral hearing implant system with an ITD processing module that estimates frequency-specific ITDs and adjusts interaural level differences (ILDs) to generate electrode stimulation signals, using ITD information from audio input signals, band pass signals, and stimulation pulse requests to enhance ITD perception and speech understanding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If cochlear implant systems rely primarily on envelope ITD information, then the system complexity is reduced, but sound localization accuracy and speech understanding in noisy environments deteriorate
Solution Approach 1:
The patent segments ITD information into two distinct components: envelope ITD and fine structure ITD. Each component is processed separately through dedicated processing paths, allowing the system to utilize both types of information without overwhelming complexity. The fine structure ITD is extracted through modulation depth calculation and temporal correlation analysis, while envelope ITD is processed through traditional methods, and both contribute to the final binaural processing.
Solution Approach 2:
The patent adds a new dimension to ITD processing by incorporating fine structure ITD information alongside the traditional envelope ITD. This creates a multi-dimensional approach where both envelope and fine structure components contribute independently to sound localization and speech understanding, effectively utilizing temporal information from different signal aspects.
2Reliability
If cochlear implant systems integrate fine structure ITD information, then speech understanding in noisy environments is improved, but device complexity increases
Solution Approach 1:
The system segments the audio signal into multiple frequency channels and separately processes fine structure and envelope information for each channel. This segmentation allows fine structure ITD to be extracted and integrated without requiring complete redesign of the entire signal processing architecture, thereby managing complexity while improving speech understanding reliability.
Solution Approach 2:
The patent performs preliminary extraction of fine structure ITD information through modulation depth calculation and temporal correlation analysis before integrating it with envelope ITD. This preliminary processing prepares the fine structure data in advance, making its integration into the binaural processing more efficient and less complex.
3Measurement precision
If the system uses both envelope ITD and fine structure ITD information, then lateralization accuracy is improved, but processing time and computational load increase
Solution Approach 1:
The system implements periodic updating of fine structure ITD estimates through modulation depth calculation and temporal correlation analysis. By updating these estimates at appropriate intervals rather than continuously, the system maintains accurate lateralization information while managing computational load and processing time effectively.
Solution Approach 2:
The patent applies partial processing to fine structure ITD by calculating modulation depth and temporal correlation only for channels where fine structure information is most beneficial. This selective approach focuses computational resources on critical frequency regions, improving lateralization accuracy without proportionally increasing overall processing time.
Data Source
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AI summary
Arrangements are described for generating electrode stimulation signals for stimulation contacts in implanted electrode arrays of a bilateral hearing implant system having electrode arrays on both the left- and right-sides. Left-side and right-side audio input signals are processed to generate corresponding left-side and right-side band pass signals, which each represent an associated band of audio frequencies in the audio input signal. Frequency-specific interaural time delays (ITDs) are estimated for the band pass signals, and the estimated ITDs are used to adjust interaural level differences (ILDs) in the band pass signals. The adjusted band pass signals then are used to generate left-side and right-side electrode stimulation signals for the stimulation contacts in the corresponding left-side and right-side electrode arrays.