Cochlear Implant Loudness Mapping With Adaptive Knee Points
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cochlear implants lack adaptive signal processing techniques to effectively map acoustic energy levels to electrical stimulation levels, leading to suboptimal sound perception in varying environments, particularly in speech situations.
Innovation Solution
The cochlear implant employs an enhanced mapping function with an intermediate knee point, allowing for level expansion below the threshold and level compression above, dynamically adjusting electrical stimulation based on the user's environment through a signal level detector and processing unit, which determines the intermediate knee point for each frequency band to improve speech decoding and overall sound perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional mapping techniques are used to map acoustic signal levels to electrical stimulation levels, then the device structure remains simple, but the adaptability to different acoustic environments and speech situations deteriorates
Solution Approach 1:
The mapping function is made dynamic by introducing an adjustable knee point parameter that can be modified in real-time based on the detected acoustic environment. The signal processing circuit dynamically adjusts the knee point value according to different speech situations (quiet, moderate, loud backgrounds) to optimize the mapping between acoustic and electrical domains, transforming a static mapping function into an adaptive one that responds to environmental changes
Solution Approach 2:
The invention changes the parameter of the mapping function (specifically the knee point value) to adapt to different acoustic conditions. By modifying this critical parameter based on environment classification, the system achieves versatile adaptation without requiring complete redesign of the mapping architecture, balancing adaptability improvement with controlled complexity increase
2Measurement precision
If a fixed mapping function is used between acoustic and electrical domains, then the device complexity is low, but the measurement precision of sound loudness mapping deteriorates in varying environments
Solution Approach 1:
The system implements feedback by continuously monitoring the acoustic environment through the acoustic signal processor, classifying the speech situation, and using this information to adjust the knee point parameter of the mapping function. This closed-loop feedback mechanism ensures that the mapping precision is optimized for the current acoustic conditions, improving loudness mapping accuracy across varying environments
Solution Approach 2:
The signal processing circuit performs preliminary classification of the acoustic environment before applying the mapping function. By pre-classifying the speech situation (quiet, moderate, loud) and selecting appropriate knee point values in advance, the system prepares the optimal mapping parameters before actual sound processing occurs, ensuring high precision without real-time computational delays
3Loss of information
If the entire dynamic range of acoustic signals is mapped linearly to electrical stimulation levels, then the manufacturing precision is simple, but the loss of information in speech situations deteriorates
Solution Approach 1:
The mapping function applies different local characteristics to different portions of the acoustic dynamic range by introducing an adjustable knee point. Below the knee point, one mapping characteristic is applied, while above it, another characteristic is applied. This local differentiation allows speech information in different intensity ranges to be preserved with appropriate weighting, reducing overall information loss
Solution Approach 2:
The acoustic dynamic range is segmented into different regions by the knee point parameter, with each region processed differently in the mapping function. This segmentation allows the system to prioritize preservation of speech information in critical intensity ranges while managing the overall dynamic range, reducing information loss through region-specific processing
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
This approach provides a more realistic mapping of sound loudness, enhancing the user's ability to understand speech in different environments by applying level expansion and compression, thereby improving the overall auditory experience.
Implementation Method 1
an input transducer for receiving an incoming acoustic signal from a user's surroundings and providing a corresponding electric input signal
Implementation Method 2
a (typically wireless, e.g. inductive) communication link for simultaneously transmitting information about the stimulation sequences and for transferring energy
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A cochlear implant is disclosed in an embodiment. The implant includes a signal level detector configured to determine a total signal level of an incoming acoustic signal and a processing unit configured to determine, in accordance with the determined total signal level, an intermediate knee point for each of a plurality of frequency bands. The implant includes a bandpass filters configured to generate a plurality of band limited audio signals in dependence upon the incoming acoustic signal, each band limited acoustic signal representing an associated audio frequency range relating to at least one electrode of a plurality of an implanted electrode array of the cochlear implant. The implant includes a pulse controller configured to deliver electrical stimulation signals to the plurality of electrodes of the implanted electrode array based on the generated signals and the determined intermediate knee point corresponding to the frequency range.