Adaptive Frequency Transposition in Hearing Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hearing devices face challenges in effectively improving speech intelligibility and making environmental sounds accessible, particularly in severe-profound hearing loss cases, where conventional amplification fails to render high-frequency speech components audible.
Innovation Solution
The hearing device employs a configurable frequency transposition unit that adjusts the weight factors α and β based on signal-to-noise ratio and level estimates to transform sound frequency sub-bands, ensuring that the destination frequency sub-band is a weighted combination of the source and destination sub-bands, optimizing speech intelligibility and sound quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional amplification is used to increase sound levels, then overall loudness is improved, but high-frequency speech components remain inaudible in severe-profound hearing loss cases
Solution Approach 1:
The patent applies frequency transposition by changing the frequency parameter of sound signals. High-frequency speech components are transposed to lower frequency ranges where the user has residual hearing, making them audible while preserving the intelligibility information contained in those high-frequency components
Solution Approach 2:
The patent moves frequency information from one dimensional range (high frequency) to another dimensional range (low frequency). This dimensional transformation allows speech components to be presented in a frequency region where the user's auditory system can detect them, effectively adding a new dimension to the hearing experience
2Manufacturing precision
If frequency transposition is applied to improve speech intelligibility, then high-frequency components become audible, but speech intelligibility may deteriorate due to loss of phase relationships
Solution Approach 1:
The patent dynamically adjusts the transposition parameters including the destination frequency selection and weighting factors based on the signal-to-noise ratio and level estimates. This dynamic adaptation optimizes speech intelligibility by preserving phase relationships when conditions are favorable while still providing frequency transposition benefits when needed
Solution Approach 2:
The patent uses feedback mechanisms by continuously estimating signal-to-noise ratio and signal levels to adaptively control the frequency transposition process. This feedback allows the system to maintain speech intelligibility by adjusting transposition parameters based on real-time acoustic conditions
3Adaptability or versatility
If frequency transposition is used to make high-frequency sounds audible, then accessibility of environmental sounds is improved, but device complexity increases due to additional processing requirements
Solution Approach 1:
The patent segments the frequency spectrum into different bands and applies frequency transposition selectively to specific source frequency bands. This segmentation approach allows the device to process only the necessary frequency ranges, reducing overall processing complexity while still providing broad frequency range accessibility
Solution Approach 2:
The patent implements a configurable frequency transposition unit that can operate in multiple modes and adapt to different listening conditions. This multi-functional design allows a single processing module to handle various scenarios (different SNR conditions, different frequency bands, different user preferences), reducing the need for separate dedicated processing chains
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
Ahearing device, e.g. a hearing aid, comprises • an input unit for providing at least one electric input signal representing sound in a frequency sub-band representation (k, m), where k and m are frequency and time indices, respectively, • an SNR estimation unit for estimating a signal to noise ratio and/or a level estimation unit for estimating a level of said at least one electric input signal, or a signal or signals derived therefrom, in said frequency sub-band representation, • and a configurable frequency transposition unit for transposing content of a source frequency sub-band FBS into a destination frequency sub-band FBD so that the contents of the resulting destination frequency sub-band is determined as a weighted combination of the contents of the source and destination frequency sub-bands according to the expression PDmod=αPD+βPS or MAGDmod=αMAGD+βMAGS wherein PD and MAGD are the unmodified power spectrum and magnitude, respectively, of the destination frequency sub-band before frequency transposition, PS and MAGS are the power spectrum and magnitude, respectively, of the source frequency sub-band, and PDmod and MAGDmod are the resulting power spectrum and magnitude, respectively, in the resulting destination sub-band after the frequency transposition, and the parameters α and β are destination and source band weight factors, respectively, that specify details of the frequency transposition operation. The configurable frequency transposition unit is configured to determine at least one of said weight factors α and β in dependence of said estimate of signal to noise ratio and/or said estimate of level of said at least one electric input signal or a signal or signals derived therefrom. A method of operating a hearing device is further disclosed.