Hearing Device Feedback Suppression Using Dynamic Probe Signal
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Solution Overview
Problem
Existing hearing devices face discomfort and pain during the initialisation process due to the high-level probe signal required for accurate feedback suppression, especially in open solutions where feedback paths have long impulse responses, necessitating a longer probe signal duration.
Innovation Solution
A new initialisation process is introduced where the probe signal level is decreased at the end of the initialisation process, utilising the 'peak/end rule' and 'duration neglect' principles to reduce user discomfort, allowing the signal level to be lower than previous levels, and the duration of the probe signal to be minimized while maintaining effective feedback path estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high-level probe signal is used during initialisation, then accurate feedback path estimation is achieved, but user discomfort and pain increase
Solution Approach 1:
The probe signal is transmitted in periodic segments with varying signal levels. The initialisation process is divided into multiple measurement segments where the signal level is adjusted based on the progress of feedback path estimation, allowing accurate measurement while reducing user discomfort in later segments.
Solution Approach 2:
The signal level parameter of the probe signal is dynamically changed during the initialisation process. The signal level is reduced in later measurement segments after the feedback path has been partially estimated, thereby maintaining measurement accuracy while reducing user discomfort and pain.
2Measurement precision
If the probe signal duration is extended to accommodate long impulse responses in open solutions, then accurate feedback suppression is achieved, but user discomfort increases
Solution Approach 1:
The initialisation process is divided into periodic measurement segments. Each segment captures a portion of the feedback path characteristics, allowing the system to build up an accurate model over time without requiring the user to tolerate a continuously high-level signal for the entire duration.
Solution Approach 2:
The signal level is made dynamic rather than static throughout the measurement process. The system adapts the signal level based on the measurement progress and the characteristics of the feedback path being measured, optimizing both accuracy and user comfort at different stages.
Data Source
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AI summary
A new method of modelling a feedback path from a receiver to a microphone in a hearing device, e.g. a hearing aid, is provided, the method comprising transmitting an electronic probe signal with a maximum allowable signal level and duration to the receiver for conversion into an acoustic probe signal output by the receiver while recording the microphone output signal, determining at least one parameter of the feedback path based on the recorded microphone output signal, and finalizing the transmitting by decreasing the signal level of the probe signal so that the modelling is terminated with a signal level of the probe signal that is smaller than a previous signal level of the probe signal, whereby discomfort experienced by the user listening to the probe signal is alleviated, since decreasing the signal level of the probe signal at the end of the initialisation process is perceived less disturbing due to the so-called "peak/end rule" and "duration neglect" discovered by Nobel Prize winner in Economics Daniel Kahneman.