�1����
Scope����������
�2����
References�
�3����
Definitions�
������� 3.1����
Terms defined elsewhere�����������
������� 3.2����
Terms defined in this Recommendation�
�4����
Abbreviations and acronyms
�5����
Conventions�������������
�6����
Introduction to ITU-T P.863�
������� 6.1����
History of objective speech quality��������
������� 6.2����
Basics of a subjective test����������
������� 6.3����
Benefit of using Recommendation ITU-T P.863��
������� 6.4����
Relationship with other Recommendations����������
������� 6.5����
Moving from ITU-T P.862 to ITU-T P.863������������
������� 6.6����
Challenges with ITU-T P.863����
������� 6.7����
MOS misconceptions���
�7����
Operational modes��
������� 7.1����
Why two operational modes?����
������� 7.2����
When should the narrowband mode be used?������
������� 7.3����
When should the superwideband mode be used?
������� 7.4����
Why no wideband (up to 7 kHz) mode?�
������� 7.5����
Are narrowband signals scored equally in narrowband and superwideband
modes?
������� 7.6����
Can I map a narrowband score to a superwideband score?��������������
����� ��7.7����
Is it recommended to mix bandwidths in subjective testing?�����������
�8����
Influence of reference speech on scores����������
������� 8.1����
What characteristics should a reference signal contain?���
������� 8.2����
Are there constraints on the recording environment?��������
������� 8.3����
Can we use artificial speech signals?������
������� 8.4����
What filter specification should be used?�������������
������� 8.5����
Does reference material influence scores?�����������
������� 8.6����
How much reference material should I use?���������
������� 8.7����
What is the impact of silence padding?��
������� 8.8����
How do I validate a reference signal?�����
������� 8.9����
How do I use a 10 minute reference file?��������������
�9����
How to inject test signals�������
������� 9.1����
Over which interfaces can signals be injected into a network?�������
������� 9.2����
Should the test signal be filtered?������������
������� 9.3����
What level should be used?�������
10����
Influence of recording process on scores��������
������ 10.1����
What influence does file speech level have on score?�����
������ 10.2����
Should we pre-align signal levels?���������
������ 10.3����
Should we apply a filter to the recording?�����������
������ 10.4����
Does ITU-T P.863 handle silence padding?���������
������ 10.5����
Can I assess a narrowband recording in superwideband mode?����
11����
Behaviour of ITU-T P.863���
������ 11.1����
Global level changes��
������ 11.2����
Local level changes����
������ 11.3����
Bandwidth limitations
������ 11.4����
Stretching and compressing speech�������
������ 11.5����
Step delay changes������
������ 11.6����
Long-term gaps in speech���������
������ 11.7����
Short-term gaps in speech���������
������ 11.8����
Cellular handovers������
12����
Comparison of ITU-T P.862.1/ITU-T P.862.2 and ITU-T P.863
������ 12.1����
Scale differences���������
������ 12.2����
Degradation handling differences����������
������ 12.3����
Standard codecs����������
13����
Procedure for comparing subjective test results to ITU-T P.863 results�
14����
Validation scope�����
������ 14.1����
Validated�������
������ 14.2����
Not yet validated���������
������ 14.3����
Outside scope��������������
Appendix I � ITU-T P.863 Reference validation checks����
Appendix II � Typical scores expected from ITU-T P.863 for a given
codec����
Appendix III � Applications for further investigation����
Bibliography����