Adaptive Hearing Level Estimation for Noise-Robust Speech Perception
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio processing devices, such as hearing aids, face challenges in accurately estimating sound levels due to the influence of stationary narrowband noise, which can mask low-level signal content like speech, leading to decreased intelligibility and improper amplification.
Innovation Solution
A hybrid level estimation approach is proposed, utilizing a high-resolution level estimator in many frequency bands for slowly varying signals and a low-resolution estimator in few frequency bands for fast varying signals, with a fading scheme to combine the estimates, ensuring proper sound perception and speech intelligibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high-resolution level estimator is used in many frequency bands, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The frequency spectrum is divided into multiple frequency bands, with different resolution levels applied to different bands. A first level estimator provides high-resolution estimates in a first number of frequency bands, while a second level estimator provides low-resolution estimates in a second number of frequency bands. This segmentation allows the system to achieve high measurement precision where needed while reducing overall device complexity through selective application of estimation resolution.
2Device complexity
If a low-resolution level estimator is used in few frequency bands, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
Different quality levels of estimation are applied locally to different frequency bands based on their specific requirements. The system identifies which frequency bands require high-resolution estimation and which can tolerate low-resolution estimation, applying the appropriate estimator type to each band. This local quality approach ensures measurement precision is maintained in critical bands while reducing device complexity in less critical bands.
3Measurement precision
If high-resolution estimates are used for all frequency bands, then measurement precision is improved, but processing time increases
Solution Approach 1:
Instead of applying high-resolution estimation to all frequency bands, the system applies high-resolution estimation only to the necessary subset of bands where it is truly needed, while using low-resolution estimation for the remaining bands. This partial action approach maintains measurement precision in critical frequency regions while significantly reducing the overall processing time and computational load.
4Measurement precision
If the number of frequency bands is increased, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The system dynamically adjusts the number of frequency bands and estimation resolution based on the specific signal characteristics and processing requirements. Rather than using a fixed high number of frequency bands for all conditions, the system can adaptively select the appropriate number of bands and resolution level needed for the current acoustic environment, maintaining measurement precision while reducing device complexity when full resolution is not required.
Data Source
AI summary
An adaptive level estimator for providing a level estimate of an electric input signal representing sound is provided. The adaptive level estimator comprisesa first level estimator configured to provide a first level estimate of the electric input signal in a first number K1 of frequency bands;a second level estimator configured to provide a second level estimate of the electric input signal and/or associated attack/release time constants in a second number K2 of frequency bands, wherein K2 is smaller than K1; anda level control unit receiving said first and second level estimates and configured to provide said resulting level estimate based on said first and said second level estimates and/or said associated attack/release time constants.The invention may e.g. be used in devices or applications that benefit from a dynamic adaptation of an input signal level to a listener's (possibly limited) dynamic range of sound level perception, or to any other specific dynamic range deviating from that of the environment sound.