Monaural Speech Intelligibility Predictor for Hearing Aids

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Solution Overview

Problem

Current technologies face challenges in predicting the intelligibility of noisy or processed speech signals without a noise-free reference signal, and in enhancing speech intelligibility in both monaural and binaural hearing scenarios.

Innovation Solution

A monaural speech intelligibility predictor unit processes time-frequency representations of speech signals to estimate intelligibility by normalizing and transforming time-frequency segments, using statistical methods and voice activity detection, and a binaural system combines monaural predictors to enhance intelligibility by adapting signal processing based on predicted intelligibility measures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If non-intrusive prediction method is used (without noise-free reference signal), then ease of operation is improved, but measurement precision deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidmeasurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary statistical model that represents the relationship between observed noisy time-frequency segments and the unobservable noise-free segments. This model acts as a mediator that allows prediction of intelligibility without direct access to noise-free reference signals, resolving the contradiction between ease of operation and measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a statistical copy or representation of the noise-free speech characteristics through the estimated parameters in the statistical model. Instead of requiring actual noise-free signals, the system uses this statistical copy to predict intelligibility, maintaining precision while improving operational ease.

Inventive Principle:
Principle #26Copying

2Device complexity

If statistical methods are used to estimate noise-free segments, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transforms the complex problem of noise-free signal estimation into a parameter estimation problem. By changing the approach from direct signal processing to statistical parameter modeling, the system reduces computational complexity while maintaining measurement precision through the use of estimated parameters that capture essential speech characteristics.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If monaural prediction is used, then device complexity is reduced, but measurement precision deteriorates compared to binaural

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent creates a universal prediction framework that can operate in both monaural and binaural modes. The core statistical modeling approach remains the same, but the system can adapt to different input configurations (single channel or dual channel), providing multi-functionality that resolves the contradiction between device complexity and measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3203473B1A monaural speech intelligibility predictor unit, a hearing aid and a binaural hearing system
Publication Date: 2024.04.10 OTICON
  • EP3203473B1 patent drawingFigure 1A~1B
  • EP3203473B1 patent drawingFigure 2A~2B
  • EP3203473B1 patent drawingFigure 3A~3D

AI summary

Signal processing methods for predicting the intelligibility of speech, e.g., in the form of an index that correlate highly with the fraction of words that an average listener (amongst a group of listeners with similar hearing profiles) would be able to understand from some speech material are proposed. Specifically, solutions to the problem of predicting the intelligibility of speech signals, which are distorted, e.g., by noise or reverberation, and which might have been passed through some signal processing device, e.g., a hearing aid are described. In summary, the disclosure present solutions to the following problems: 1. Monaural, non-intrusive intelligibility prediction of noisy/processed speech signals 2. Binaural, non-intrusive intelligibility prediction of noisy/processed speech signals 3. Monaural and binaural intelligibility enhancement of noisy speech signals.