Summary

This Recommendation gives a methodology for deriving equipment impairment factors (Ies) for digital signal processing devices, namely low bit-rate codecs. The Ie values are intended to be used as an input to the E-Model (see ITU-T Rec. G.107).

The present methodology makes use of instrumental models (so-called "objective methods"), e.g., of the model defined in ITU-T Rec. P.862. It is to be considered as supplementary to the methodology based on auditory listening-only tests, described in ITU-T Rec. P.833. It will provide valid Ie values only for those codecs for which the used instrumental model produces meaningful estimations.

This Recommendation includes an electronic attachment containing speech material.