This is an interesting application of the recorded interview in psychotherapy. The recording of the patient's voice is played back to him to demonstrate the unconscious character defenses in the tone of the voice. 'The tone of the voice revealed to the patients how babyish they were and how they irked people by their incessant complaints and bids for affection.' Freed also cites the use of the recorded interview in narcosynthesis and narcoanalysis. The patient is later faced with the material thus obtained. In postoperative lobotomies it was used to demonstrate postoperative progress and the loss of tension compared with the preoperative state.