End-to-End Pronunciation Scoring Without Forced Alignment

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Solution Overview

Problem

Existing pronunciation assessment technologies for non-native speakers require forced alignment and text information, limiting their effectiveness and applicability.

Innovation Solution

A foreign language pronunciation assessment apparatus using a transformer structure-based end-to-end speech recognizer that trains on native speaker data, tunes with non-native speaker data, and calculates a prediction score through a scoring module, eliminating the need for forced alignment and text information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If forced alignment and text information are used for pronunciation assessment, then measurement precision can be improved, but device complexity and ease of operation deteriorate

Engineering Contradiction:
Improvepronunciation assessment accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the forced alignment step and text information requirement from the pronunciation assessment system. By using an end-to-end speech recognition model that directly processes speech signals without requiring intermediate text alignment, the system eliminates complex preprocessing steps while maintaining assessment accuracy

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The end-to-end speech recognition model serves multiple functions simultaneously: it performs speech recognition, pronunciation assessment, and scoring in a single unified system. This multi-functional approach replaces the need for separate forced alignment tools and text processing components, reducing overall system complexity

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

2Measurement precision

If forced alignment is performed for pronunciation assessment, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvepronunciation assessment accuracyVSAvoidassessment processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The speech recognition model is pre-trained on large datasets of native speaker speech before deployment. This preliminary training phase allows the model to learn pronunciation patterns and assessment criteria in advance, enabling it to perform accurate assessments without requiring time-consuming forced alignment during actual use

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The end-to-end model processes speech signals continuously in a single pass, eliminating the need for separate forced alignment steps that interrupt the assessment workflow. The model maintains continuous processing from raw speech input to final score output, reducing total assessment time

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If text information is required for training ASR system, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvespeech recognition accuracyVSAvoidsystem usability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system uses native speaker speech data that is automatically collected and processed without requiring manual text transcription or annotation. The model learns to associate speech patterns with pronunciation quality directly from audio data, making the training process more automated and easier to operate

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical process of manual text creation and alignment with a learning-based approach. The end-to-end speech recognition model automatically learns to map speech signals to pronunciation assessments through training on labeled speech data, eliminating the need for manual text preparation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12469484B2Foreign language pronunciation assessment apparatus and control method thereof
Publication Date: 2025.11.11 KAKAO ENTERPRISE CORP
  • US12469484B2 patent drawing
  • US12469484B2 patent drawing
  • US12469484B2 patent drawing

AI summary

A technology for assessing foreign language pronunciation of a non-native learner is provided. The foreign language pronunciation assessment technology includes training an end-to-end speech recognizer with native speaker data, tuning the trained end-to-end speech recognizer with non-native speaker data, training a scoring module on the basis of the finely tuned end-to-end speech recognizer, and calculating, by the trained scoring module, a prediction score for non-native speaker speech input when the non-native speaker speech is input to the tuned end-to-end speech recognizer.