THE ADVENT of the tape recorder added an instrument to teaching and Psychotherapy which has many possibilities but about which relatively little has been written. Perhaps its most obvious use is the recording of full therapy sessions for research study,1 for discussion with a supervisor,2 or even as a permanent record. Recordings have also been used for seminar teaching.2 For such purposes, video tape has obvious advantages and is beginning to be studied.3 The process of supervision itself has also been studied through recording of sessions.4 An additional dimension, however, can be added by both members of the diad, whether patient and therapist or supervisor and supervisee, listening together to the recordings. The present project was stimulated by my interest in the supervisory process, and by the observations of Geocaris5 on the impact of patients listening to their own psychotherapy