First International Conference on Spoken Language Processing (ICSLP 90)

Kobe, Japan
November 18-22, 1990

Glottal-LPC Based Coding of Telephone Band Vowels With Simple All-Pole Excitation

Paavo Alku

Helsinki University of Technology, Acoustics Laboratory, Espoo, Finland

The coding of telephone band vowels has been studied in this research by using a speech production model that consists of three separated parts: the glottal excitation, the vocal tract and the lip radiation effect. The processes were identified and computed using the AIF-method. In the coding procedure the obtained glottal excitation was replaced by impulse responses of low order LPC-filters. The difference between the time domain characteristics of the original and the coded excitation is extensive but their frequency domain curves are similar. The vocal tract and the lip radiation effects were coded as an eigth order LPC-filter and a differentiator, respectively. The results of this study serve as a promising basis for further studies in order to create a low bit rate speech coder that is based on a more reliable modeling of speech production in comparison to conventional LPC.

Full Paper

Bibliographic reference.  Alku, Paavo (1990): "Glottal-LPC based coding of telephone band vowels with simple all-pole excitation", In ICSLP-1990, 89-92.