AN EVALUATION OF SPEECH COMPRESSION SYSTEMS

Abstract

The results of PB word and nonsense syllable intelligibility tests, voice quality, talker identification, and continuous speech tests of selected speech compression systems are presented. The systems were: a reference low-pass (approximately 3000 cps) filter system, two channel vocoders, a semi-vocoder, a formant-tracking vocoder and a multiple narrow band filter system. Different speech compression techniques are classified according to their ability to provide a given level of speech intelligibility at different information rates. Channel vocoders operating at about 2400 bits/sec and semi-vocoders at an estimated 9600 bits/sec provide adequate intelligibility and quality for most military communications; the quality of the semi-vocoder is superior to the channel vocoder. Formant-tracking vocoders utilize the lowest information rate (about 1000 bits/sec) of any of the bandwidth compression techniques. Formant- tracking vocoders require further improvement before they can be as satisfactory for general use.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1962
Accession Number
AD0277457

Entities

People

  • Karl D. Kryter
  • Kenneth N. Stevens
  • Michael H. Hecker

Organizations

  • BBN Technologies

Tags

Communities of Interest

  • Energy and Power Technologies
  • Human Systems

DTIC Thesaurus Topics

  • Analysis Of Variance
  • Bandwidth
  • Communication Systems
  • Compression
  • Data Processing
  • Frequency Bands
  • Identification
  • Intelligibility
  • Larynx
  • Measurement
  • Military Communications
  • Performance Tests
  • Speech
  • Speech Compression
  • Tape Recording
  • Voice Communications
  • Waveforms

Readers

  • Radio communications and signal processing.
  • Speech Processing/Speech Recognition.

Technology Areas

  • Fully Networked C3
  • Fully Networked C3 - Command and Control