Template Based Low Data Rate Speech Encoder

Abstract

The 2400-b/s linear predictive coder (LPC) is currently being widely deployed to support tactical voice communication over narrowband channels. However, there is a need for lower-data-rate voice encoders for special applications: improved performance in high bit-error conditions, low- probability-of-intercept (LPI) voice communication, and narrowband integrated voice/data systems. An 800-b/s voice encoding algorithm is presented which is an extension of the 2400-b/s LPC. To construct template tables, speech samples of 420 speakers uttering 8 sentences each were excerpted from the Texas Instrument - Massachusetts Institute of Technology (TIMIT) Acoustic-Phonetic Speech Data Base. Speech intelligibility of the 800-b/s voice encoding algorithm measured by the diagnostic rhyme test (DRT) is 91.5 for three male speakers. This score compares favorably with the 2400-b/s LPC of a few years ago.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1993
Accession Number
ADA270900

Entities

People

  • Lawrence Fransen

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Human Systems

DTIC Thesaurus Topics

  • Abstracts
  • Algorithms
  • Coders
  • Coding
  • Computer Programming
  • Data Rate
  • Decoding
  • Frequency
  • Human Factors Engineering
  • Intelligibility
  • Line Spectra
  • Narrowband
  • Software Development
  • Spectra
  • Speech
  • Template Patterns
  • Voice Communications

Fields of Study

  • Computer science

Readers

  • Speech Processing/Speech Recognition.