8th European Conference on Speech Communication and Technology

Geneva, Switzerland
September 1-4, 2003


Exploiting Time Warping in AMR-NB and AMR-WB Speech Coders

Lasse Laaksonen (1), Sakari Himanen (2), Ari Heikkinen (2), Jani Nurminen (2)

(1) Tampere University of Technology, Finland
(2) Nokia Research Center, Finland

In this paper, a time warping algorithm is implemented and its performance is evaluated in the context of Adaptive Multi- Rate (AMR) wideband (WB) and narrowband (NB) speech coders. The aim of time warping is to achieve bit savings in transmission of pitch information with no significant quality degradations. In the case of AMR-NB and AMR-WB speech coders, these bit savings are 0.65-1.15 kbit/s depending on the mode. The performance of the modified AMR speech coders is verified by subjective and objective measures in error-free conditions. MOS tests show that only slight, statistically insignificant degradation of speech quality is experienced when time warping is implemented.

Full Paper

Bibliographic reference.  Laaksonen, Lasse / Himanen, Sakari / Heikkinen, Ari / Nurminen, Jani (2003): "Exploiting time warping in AMR-NB and AMR-WB speech coders", In EUROSPEECH-2003, 1729-1732.