scope:

The present document describes testing methodologies which can be used to objectively evaluate the performance of narrowband and wideband mobile terminals for speech communication in the presence of background noise.

Background noise is a problem in mostly all situations and conditions and needs to be taken into account in both, terminals and networks. The present document provides information about the testing methods applicable to objectively evaluate the speech quality of mobile terminals with AMR and AMR-WB codecs in the presence of background noise. The present document includes:

• The method which is applicable to objectively determine the different parameters influencing the speech quality in the presence of background noise taking into account:

- the speech quality;

- the background noise transmission quality;

- the overall quality.

• The description of the adaptation of the test method described in ETSI ES 202 396-1 [i.2].

• The model results in comparison with the underlying subjective tests used for the retraining of the objective model.

• The model validation results:

- Additional validation results are provided for cases which include some conditions outside the scope of ETSI ES 202 396-1 [i.2]. These include music as background noise, and user holding a handset in other than nominal position, as defined in Recommendation ITU-T P.64 [i.24]. In addition, validation results are provided for Chinese language.

The present document is to be used in conjunction with:

- ETSI ES 202 396-1 [i.2] which describes a recording and reproduction setup for realistic simulation of background noise scenarios in lab-type environments for the performance evaluation of terminals and communication systems.

- ETSI EG 202 396-3 [i.4] which describes the basic objective model underlying to the Model described in the present document.

- American English speech sentences as enclosed in the present document.

The prediction of performance for narrowband and wideband mobile terminals, which feature artificial intelligence-based speech enhancement techniques, is out of scope. Devices employing such techniques were not available for training and validation of the present model.