Wideband speech codecs usually provide better perceptual speech quality than their narrowband counterparts, but they still degrade quality compared to an uncoded transmission path. In order to quantify these degradations, a new methodology is presented which derives a one-dimensional quality index on the basis of instrumental measurements. This index can be used to rank different wideband speech codecs according to their degradations and to calculate overall quality in conjunction with other degradations, like packet loss. We apply this methodology to derive respective indices for the new G.711.1 codec.
Bibliographic reference. Möller, Sebastian / Côté, Nicolas / Kurashima, Atsuko / Egi, Noritsugu / Takahashi, Akira (2009): "Quantifying wideband speech codec degradations via impairment factors: the new ITU-t p.834.1 methodology and its application to the g.711.1 codec", In INTERSPEECH-2009, 2563-2566.