An LPC vocoder based on phase-equalized pitch waveform

Yusuke Hiwasaki*, Kazunori Mano, Takao Kaneko

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


This paper presents a speech coder operating at a very low bit-rate using a model called "phase-equalized pitch waveform". The basic idea of the coder is to employ pitchwise extraction of the linear predictive residual signal, a pitch waveform, in voiced speech. The residual signal is processed with a phase-equalization filter to increase the efficiency of both the pitch waveform quantization and interpolation. Listening tests showed that efficient and high-quality coding is achieved at 2.0 kbits/s. The quality of the coder is equal to that of the DoD FS1016 standard CELP at 4.8 or 2.4 kbits/s MELP.

Original languageEnglish
Pages (from-to)277-290
Number of pages14
JournalSpeech Communication
Issue number3
Publication statusPublished - 2003 May
Externally publishedYes


  • LPC vocoder
  • Phase equalization
  • Pitch waveform
  • Speech coding
  • Vector quantization

ASJC Scopus subject areas

  • Software
  • Modelling and Simulation
  • Communication
  • Language and Linguistics
  • Linguistics and Language
  • Computer Vision and Pattern Recognition
  • Computer Science Applications


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