�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���� How to use this Recommendation��
������� 6.1���� Determining compliance with this Recommendation��
������� 6.2���� Testing at different stages of the development cycle��
������� 6.3���� Application of this Recommendation to acoustic zoning concepts���������
�7���� Test arrangement��
������� 7.1���� Test arrangement in a car�������
�8���� Test signals and test signal
levels����
�9���� Measurement parameters and
requirements for hands-free terminals����������
������� 9.1���� Delay
������� 9.2���� Loudness ratings���������
������� 9.3���� Loudness�������
������� 9.4���� Sensitivity frequency responses�����������
������� 9.5���� Listening speech quality during single talk��������
������� 9.6���� Listening speech
quality stability����������
������� 9.7���� Idle channel noise������
������� 9.8���� Distortion in send������
������� 9.9���� Distortion in receive�
������ 9.10���� Echo performance����
������ 9.11���� Switching characteristics��������
������ 9.12���� Double talk
performance������
������ 9.13���� Background noise
transmission�����������
10���� Guidance on subjective testing�������
Annex A � Speech quality measurements����
Annex B � Principles of Relative Approach����
Annex C � Example for a questionnaire for subjective testing����
�C���� Performance rating
������� C.1���� Overview�������
������� C.2���� Test categories and rating types����������
������� C.3���� Speech and background noise quality in send direction��������������
������� C.4���� Speech quality in receive direction (in the car under test)���������
������� C.5���� Echo cancellation performance������������
������� C.6���� Hands-free system stability tests (car-to-car)�
Annex D � Standard set of user scenarios����
Annex E � System stability with insufficient far‑end echo loss����
Annex F � Microphone related sound field reproduction technique � multi-point
noise simulation (MPNS) method����
������� F.1���� Loudspeaker set-up in the car
��� ����F.2���� Microphone set-up in the car�
������� F.3���� Background noise recordings and reference noise�������
������� F.4���� Equalization��
������� F.5���� Accuracy of the
equalization��
Bibliography����