Volunteer subjects who gave informed consent listened through earphones to music of their own choice on stereophonic tape,
sitting in a quiet, darkened room. Raising one finger signified a definite thrill of lowest intensity and localized, two fingers
a stronger thrill with some spread, three fingers a maximum intensity thrill spreading widely to distant parts of the body.
Duration was indicated by the length of time the finger(s) remained raised. I sat nearby, wearing earphones too, and recording the time, intensity, and duration of each thrill episode to the nearest second.
In preliminary experiments, saline or naloxone hydrochloride (10 mg/ml) was injected intravenously in a double·blind manner,
between two auditions of the same musical passage. Thrill scores, based on frequency, intensity, and duration, were compared for the preinjection and postinjection audition.