Semi-Word Acoustic Model for Speech Recognition Vocabulary Contraction

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Solution Overview

Problem

Large language vocabularies in speech recognition systems require significant storage space and result in limited accuracy due to their unbounded nature and continuous addition of new words, making it challenging to efficiently process and recognize human speech.

Innovation Solution

The system restructures conventional speech recognizer data by segmenting pronunciation dictionary entries into constituent phonemes and grouping them based on initial phonemes, creating a semi-word acoustic model that reduces the number of possibilities and improves recognition accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a large unbounded vocabulary is used to accommodate continuously added new words, then the system can recognize more words, but storage space requirements increase and recognition accuracy decreases

Engineering Contradiction:
Improvevocabulary coverageVSAvoidstorage space
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent segments words into phoneme sequences and groups them by common prefixes (initial N phonemes). This segmentation allows the system to handle large vocabularies by breaking them into manageable chunks that can be stored more efficiently and processed in a structured manner, reducing the storage burden while maintaining vocabulary coverage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of vocabulary organization from storing complete words to storing phoneme sequences with prefix grouping. By transforming the representation parameters (from whole words to segmented phoneme structures), the system achieves better storage efficiency while preserving the ability to recognize a large number of words.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a large unbounded vocabulary is used to accommodate continuously added new words, then the system can recognize more words, but recognition accuracy decreases

Engineering Contradiction:
Improvevocabulary coverageVSAvoidrecognition accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

By segmenting words into phoneme sequences and grouping by common prefixes, the system creates a more structured representation that improves acoustic modeling. This segmentation allows for better statistical modeling of phoneme patterns, which enhances recognition accuracy even as vocabulary size grows.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The transformation from whole-word storage to phoneme-sequence storage with prefix grouping changes the fundamental parameters of vocabulary representation. This parameter change enables more effective acoustic-phonetic modeling, which directly improves recognition accuracy by capturing phonetic patterns more effectively.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If conventional pronunciation dictionaries are used for large vocabularies, then all words can be represented, but processing efficiency decreases

Engineering Contradiction:
Improvevocabulary coverageVSAvoidprocessing efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The segmentation of vocabulary into phoneme sequences with prefix grouping enables more efficient processing by reducing the search space. When processing speech, the system can quickly identify potential matches by matching phoneme sequences and prefixes, rather than searching through entire word forms, significantly improving processing efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By changing the organizational parameters from complete words to segmented phoneme structures, the system optimizes processing efficiency. The transformed representation allows for faster acoustic matching and more efficient decoding, as the structured phoneme sequences enable better utilization of acoustic models and faster candidate generation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12008986B1Universal semi-word model for vocabulary contraction in automatic speech recognition
Publication Date: 2024.06.11 INTERACTIONS LLC (US)
  • US12008986B1 patent drawing
  • US12008986B1 patent drawing
  • US12008986B1 patent drawing

AI summary

A speech recognition system includes, or has access to, conventional speech recognizer data, including a conventional acoustic model and pronunciation dictionary. The speech recognition system generates restructured speech recognizer data from the conventional speech recognizer data. When used at runtime by a speech recognizer module, the restructured speech recognizer data produces more accurate and efficient results than those produced using the conventional speech recognizer data. The restructuring involves segmenting entries of the conventional pronunciation dictionary and acoustic model according to their constituent phonemes and grouping those entries with the same initial N phonemes, for some integer N (e.g., N=3), and deriving a restructured dictionary with a corresponding semi-word acoustic model for the various grouped entries. The decomposition of the conventional pronunciation dictionary into the restructured dictionary with semi-word acoustic model greatly reduces the number of possibilities in the dictionaries (e.g., from potentially unlimited to finite and relatively small), and also improves the accuracy of speech recognition.