Development of an objective speech quality measurement model for the AMR codec

This paper describes the development of a non-intrusive measure of speech quality for GSM AMR, based on bit error (BER) and frame error (FER) distributions together with handover events. Input to such a model is extensive listening tests on speech from AMR GSM networks to identify what type of error situations that cause poor speech quality. By using suitable mathematical/ statistical tools on the results from the listening tests and the full information about the errors and their distributions, a model of speech quality could be established. The cross-validated correlation coefficient of the model and subjective speech quality is 0.94.