Rapid Development in new languages

1
A Thai Speech Translation System for Medical
Dialogs Tanja Schultz, Dorcas Alexander, Alan W
Black, Kay Peterson, Sinaporn Suebvisai, Alex
Waibel
System Architecture
Speech Recognition

• Rapid Development in new languages
• Limited training data (6hrs) provided by NECTEC
  from 34 speakers, 8 spks for development and
  test
• Romanization of Thai script in order to
• allows non-Thai researchers to work with the
  Roman representation like in the grammar
  development
• romanized output basically provides the
  pronunciation easier for speech synthesis
  component
• Current dictionary covers the given 6-hours
  database 734 words
• Rapid bootstrapping of acoustic models using a
  7-lingual GlobalPhone model set (Ch, Cr, Fr, Ge,
  Ja, Sp, Tu)
• Results on ASR indicate that rapid bootstrapping
  can be done successfully for limited domain (see
  table)
• Word accuracy in Thai language on the
  evaluation set
• CI-AM 83.63 CD-AM (500) 84.44 CD-AM (1000)
  82.71

• Tcl/Tk based Communication Server
• Runs on Windows and Linux platforms
• Integrates several languages Thai, English,
  Spa, Ch, ...
• Integrates different speech recognition
  approaches
• Decoding along n-grams versus Context Free
  Grammars
• Integrates different translation approaches
• IF-based Translation versus statistical MT
• Integrates two natural language generations from
  IF
• knowledge-based generation with the
  pseudo-unification
• statistical generation
• Allows transmission of IF across devices for
  (wireless) multi-party translation (see demo
  Laptop ? PDA )

• Interface
• Hypothesis
• Thai Roman script
• Parse tree (CFG)
• Translation
• IF representation

Translation
Speech Synthesis

• Interlingua based Machine Translation component
  - Interchange Format (IF)
• abstracts from variation in syntax across
  languages
• allows monolingual development for analysis and
  generation
• provides paraphrase back into source language
• can be easily extended to new languages due to
  STAR structure
• Some extensions due to Thai characteristics
• The use of a term to indicate the gender of the
  person
• Thai zookhee kha1 - Eng okay (ending)
• sacknowledge (zookhee speaker)
• An affirmation that means more than simply
  "yes."
• Thai saap khrap - Eng know (ending)
• saffirmknowledge(saap speaker)
• Verb separation of terms for feasibility and
  other modalities

• First Thai voice built in the Festival Speech
  Synthesis System
• Limited domain targeting the Hotel Reservation
  domain
• 235 sentence that covered the main aspects of
  immediate interest
• Recorded, auto-labeled, and built a synthetic
  voice using FestVox tools
• Converted to small footprint portable version
  using Cepstral's Theta engine
• Rapid synthesis development in new languages
• Phoneme set shared with Speech Recognition
• Lexicon of 522 words vocabulary constructed by
  hand
• Statistically trained letter to sound rules to
  bootstrap the required word coverage
• Unit selection concatenative synthesis
• Phones tagged with syllable and tone information
  for more fluent results