CONTENTS

�1���� Introduction
�2���� References
�3���� Effect of echo
�4���� Active echo control devices
������� 4.1���� Application guidelines
�5���� Additional echo control rules
������� 5.1���� Rules for connections with echo control devices
��������� ��������5.1.1���� Ideal rules
����������������� 5.1.2���� Practical rules
������� 5.2���� General rules (for connections with or without echo control devices)
����������������� 5.2.1���� Ideal rule
����������������� 5.2.2���� Practical rules
�6���� Insertion of echo control devices in a connection
�7���� Speech processing devices
Appendix I � Assessment of talker echo effects