Multilingual Codebook Generation for Embedded Speech Recognition

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Solution Overview

Problem

Current speech recognition systems face challenges in efficiently recognizing speech inputs of different languages due to high computational resource demands, especially in embedded systems with memory and processor limitations, as existing codebook generation methods are designed for single languages and result in excessive data and processing loads when handling multiple languages.

Innovation Solution

A method for generating a multilingual codebook by iteratively adding code vectors from additional languages to a main language codebook based on distance thresholds, using algorithms like the LBG algorithm and distance measures such as Mahalanobis distance, to create a compact codebook that reduces processor load and memory requirements while maintaining recognition performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate codebooks are used for each language, then speech recognition accuracy for multiple languages is improved, but memory requirements and data volume increase significantly

Engineering Contradiction:
Improvespeech recognition accuracyVSAvoiddata volume
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges multiple language-specific codebooks into a single multilingual codebook by selecting code vectors from additional languages that are not already represented in the main language codebook. This combining approach maintains recognition accuracy for multiple languages while reducing the total data volume compared to storing separate codebooks for each language.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multilingual codebook serves as a universal data structure that handles multiple languages simultaneously. By making the codebook multi-functional for different languages, the system eliminates the need for separate language-specific codebooks, thereby reducing memory requirements while maintaining recognition capability across languages.

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

2Reliability

If separate codebooks are used for each language, then speech recognition accuracy for multiple languages is improved, but processor load increases

Engineering Contradiction:
Improvespeech recognition accuracyVSAvoidprocessor load
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent combines multiple language processing capabilities into a single unified codebook structure, allowing the processor to handle multiple languages through one data structure rather than switching between multiple separate codebooks. This reduces processor overhead and computational load.

Inventive Principle:
Principle #5Merging (Combining)

3Power

If a single codebook is used for all languages, then memory requirements and processing load are reduced, but speech recognition accuracy for minority languages deteriorates

Engineering Contradiction:
Improveprocessor loadVSAvoidspeech recognition accuracy
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent applies local quality by selectively adding code vectors from additional languages only where needed - specifically, code vectors that represent sounds not already covered in the main language codebook. This ensures that minority languages receive adequate representation without uniformly expanding the entire codebook, thereby maintaining accuracy for minority languages while controlling overall data volume.

Inventive Principle:
Principle #3Local quality

4Adaptability or versatility

If code vectors from additional languages are added to main language codebook, then multilingual recognition capability is improved, but codebook size increases

Engineering Contradiction:
Improvemultilingual recognition capabilityVSAvoidcodebook size
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent extracts only the necessary code vectors from additional language codebooks - specifically those code vectors that represent phonetic features not already present in the main language codebook. This selective extraction approach adds multilingual capability while minimizing the increase in codebook size by excluding redundant code vectors.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2107554B1Generation of multilingual codebooks for speech recognition
Publication Date: 2011.08.10 NUANCE COMMUNICATIONS INC
  • EP2107554B1 patent drawing

AI summary

The present invention relates to a method for generating a multilingual codebook, comprising the steps of providing a main language codebook, providing at least one additional codebook corresponding to a language different from the main language and generating a multilingual codebook from the main language codebook and the at least one additional codebook by adding a sub-set of the code vectors of the at least one additional codebook to the main codebook based on distances between the code vectors of the at least one additional codebook to code vectors of the main language codebook.