Frequency Compression with Selective Shifting
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Solution Overview
Problem
Existing frequency compression methods in hearing aids result in tone sequences appearing scrambled at the output, leading to a worsened auditory impression due to non-continuous mapping and artefacts.
Innovation Solution
A method involving determining a dominant instantaneous frequency in a first frequency channel, shifting it to an intermediate position, and then using a predetermined continuous compression characteristic to determine a final frequency position, with subsequent amplitude modulation to achieve precise frequency mapping, minimizing artefacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If frequency compression is implemented by simply copying channels, then implementation is simple, but tone sequences appear scrambled and auditory impression deteriorates
Solution Approach 1:
The frequency compression process is divided into two distinct stages: first, channel-by-channel copying for simple implementation; second, dominant tone detection and remapping to correct frequency ordering. This segmentation allows each stage to optimize for its specific purpose while maintaining overall system simplicity.
Solution Approach 2:
An intermediate processing stage is introduced between channel copying and final output. This intermediary detects dominant tones in source channels and applies remapping to ensure correct frequency ordering, acting as a mediator that preserves both implementation simplicity and auditory quality.
2Productivity
If channel-by-channel frequency mapping is used, then frequency compression is achieved, but non-continuous mapping causes artefacts
Solution Approach 1:
The mapping approach is changed from purely channel-based to a hybrid method that incorporates dominant tone frequency information. By detecting and remapping based on actual tone frequencies rather than fixed channel assignments, the system achieves continuous mapping that eliminates artefacts while maintaining compression efficiency.
Solution Approach 2:
The frequency mapping becomes dynamic rather than static. The system adapts the mapping based on the detected dominant tones in each channel, allowing flexible remapping that maintains continuity and reduces artefacts while preserving the efficiency of frequency compression.
3Reliability
If dominant tone remapping is added to channel copying, then tone sequence ordering is preserved, but device complexity increases
Solution Approach 1:
Instead of completely redesigning the frequency compression system, only the necessary partial action of dominant tone detection and remapping is added to the existing channel copying mechanism. This minimal addition preserves tone sequence ordering without requiring complete system restructuring.
Solution Approach 2:
Dominant tone detection and remapping are performed as preliminary steps before final channel copying and output. By preparing the frequency mapping in advance based on detected tones, the system ensures correct ordering is maintained throughout the processing chain without adding complexity to the core copying mechanism.
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 ensures continuous frequency mapping without tone sequence scrambling, enhancing the auditory experience by reducing artefacts and maintaining the correct order of frequencies.
Implementation Method 1
shifting or mapping the dominant instantaneous frequency from the intermediate frequency position to the final frequency position, in particular by amplitude modulation
Data Source
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AI summary
The method involves providing an audio signal in a frequency channel (14'). A dominant instantaneous frequency (14'') is determined in the frequency channel. The channel including the instantaneous frequency is displaced or reproduced in another channel. A permanent frequency position (fd) for the instantaneous frequency is determined by a preset compression characteristic line in the latter channel based on a frequency position (fs) of the instantaneous frequency. The instantaneous frequency is displaced or reproduced from an intermediate frequency position (fz) to the permanent position. An independent claim is also included for a device for compressing frequency of an audio signal.