Table of Contents

�1���� Scope������������
�2���� References���
�3���� Definitions���
������� 3.1���� Terms defined elsewhere
������� 3.2���� Terms defined in this Recommendation�����
�4���� Abbreviations and acronyms��
�5���� General description����
�6���� Physical characteristics�������������
������� 6.1���� General rules�����
������� 6.2���� Pin assignments
�7���� Electrical interface specification�������������
������� 7.1���� Communication mode���
������� 7.2���� Multimedia playback (provisional, for further study)��������������
�8���� Headset specification
������� 8.1���� Communication mode���
������� 8.2���� Multimedia playback mode (provisional, for further study)���
�9���� Function requirements for terminals with the universal headset interface������
Annex A � Interpolation method for diffuse-field correction����
Appendix I � Audio connectivity for sockets with four contact points����
������� I.1���� 2.5 mm diameter plug connector with four poles�������
������� I.2���� 2.5 mm diameter socket connector with four contact points��
������� I.3���� 3.5 mm diameter plug connector with four poles�������
������� I.4���� 3.5 mm diameter socket connector with four contact points��
Appendix II � Audio connectivity for sockets with four contact points (optional dimensions to accommodate terminal designs with curved edges)����
������ II.1���� 2.5 mm diameter plug connector with four poles������
������ II.2���� 3.5 mm diameter plug connector with four poles������
Appendix III � Audio connectivity for sockets with three contact points����
����� III.1���� 2.5 mm diameter plug connector with three poles����
����� III.2���� 2.5 mm diameter socket connector with three contact points
����� III.3���� 3.5 mm diameter plug connector with three poles����
����� III.4���� 3.5 mm diameter socket connector with three contact points
Appendix IV � Other considerations����
������ IV.1���� Filter recommendation��
������ IV.2���� ESD���
������ IV.3���� Microphone basics � background���������������
������ IV.4���� Vcc Voltage for microphone bias
������ IV.5���� DC resistance of microphone�������
Bibliography����