New 2-kbit/s speech coder based on normalized pitch waveform

Yuusuke Hiwasaki, Kazunori Mano

Research output: Contribution to journalConference articlepeer-review

3 Citations (Scopus)


Speech coding at very low bitrate is useful for purposes such as voice communication over computer networks. However, speech coding at around 2.0 kbit/s is difficult for CELP coders while maintaining a high quality. In this paper, a speech coding model called `normalized pitch waveform' and its quantization scheme are presented, aiming for effective compression coding of the `voiced' speech. Listening tests has proven that an efficient and high quality coding has been achieved at bitrate 2.0 kbit/s, less than half of the FS1016. Furthermore, this paper discusses the disadvantage of the normalized pitch waveform and presents an alternative method of using non-normalized pitch waveform. Encoding of a transitional `mixed' state between the `voiced' and the `unvoiced' state is discussed for further improvements.

Original languageEnglish
Pages (from-to)1583-1586
Number of pages4
JournalICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Publication statusPublished - 1997 Jan 1
EventProceedings of the 1997 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP. Part 1 (of 5) - Munich, Ger
Duration: 1997 Apr 211997 Apr 24

ASJC Scopus subject areas

  • Software
  • Signal Processing
  • Electrical and Electronic Engineering


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