�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��
�7���� Test arrangement��
������� 7.1���� Test arrangement in a car�������
�8���� Digital interfaces for development, debugging and test���������
������� 8.1���� Interfaces and access points��
������� 8.2���� Test set-up and tests
�9���� Test signals and test signal levels����
������� 9.1���� Signals�������������
������� 9.2���� Background noise signals���������
10���� Measurement parameters and requirements for microphones used in
speakerphone hands-free systems����
������ 10.1���� Microphone measurements in anechoic conditions����
������ 10.2���� Microphone measurements in the car��������������
11���� Measurement parameters and requirements for hands-free terminals���������
������ 11.1���� Preparation measurements�
������ 11.2���� Delay��������������
������ 11.3���� Loudness ratings�������
������ 11.4���� Sensitivity frequency responses���������
������ 11.5���� Speech quality during single talk���������
������ 11.6���� Listening speech quality stability���������
������ 11.7���� Idle channel noise�����
������ 11.8���� Out-of-band signals�
������ 11.9���� Distortion in send�����
����� 11.10���� Distortion in receive
����� 11.11���� Echo performance��
����� 11.12���� Double talk performance�����
����� 11.13���� Background noise transmission���������
12���� Verification of the transmission performance of short-range wireless
transmission enabled phones����
������ 12.1���� Interface definition and calibration����
������ 12.2���� SRW loudness ratings��������������
������ 12.3���� SRW sensitivity frequency responses
������ 12.4���� SRW noise cancellation test in send direction
������ 12.5���� SRW speech quality during single talk���������������
13���� Car-to-car communication
14���� Guidance on subjective testing�������
15���� Corded headsets��
������ 15.1���� Connector type����������
������ 15.2���� Connector wiring and electrical specifications��������������
������ 15.3���� Headset receive characteristics�����������
������ 15.4���� Headset transmit characteristics���������
������ 15.5���� Standard behaviour in the presence of corded headsets����������
16���� Wireless headsets
������ 16.1���� Wireless headset types����������
������ 16.2���� Test methodology for verification of standard behaviour���������
������ 16.3���� Standard behaviour in the presence of wireless headsets�������
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 method (MPNS)����
������� F.1���� Loudspeaker setup in the car�
������� F.2���� Microphone setup in the car��
������� F.3���� Background noise recordings and reference noise�������
������� F.4���� Equalization��
������� F.5���� Accuracy of the equalization��
Appendix I � A method to determine the listening speech quality����
������� I.1���� ������������ One‑way speech quality in sending���������
������� I.2���� ������������ One-way speech quality in receiving�������
Bibliography����