CONTENTS

 1     Scope
 2     References
 3     Definitions
 4     Abbreviations
 5     Conventions
 6     Summary of subjective testing procedures
 7     Source recordings
        7.1     Recording system
        7.2     Speech samples
 8     Selection of experiment parameters
        8.1     Codec conditions
        8.2     Reference conditions
 9     Experiment design
10     Listening test procedure
       10.1     Receiving system
       10.2     Opinion scales
       10.3     Electrical noise
11     Analysis of results
Annex A – Comparison of different SNR definitions
Annex B – Sets of parameters to determine codec performance
        B.1     Narrow‑band systems (300-3400 Hz)
        B.2     Wideband systems (100-7000 Hz)
Annex C – PCM codec corresponding to one qdu
        C.1     Common analogue interface
        C.2     Digital interface
        C.3     Analogue interface
Annex D – Modified IRS send and receive characteristics
Bibliography