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.
|ジャーナル||ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings|
|出版物ステータス||Published - 1997 1 1|
|イベント||Proceedings of the 1997 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP. Part 1 (of 5) - Munich, Ger|
継続期間: 1997 4 21 → 1997 4 24
ASJC Scopus subject areas
- Signal Processing
- Electrical and Electronic Engineering