Orgasm in women in the laboratory--quantitative studies on duration, intensity, latency, and vaginal blood flow.

Sexual arousal by clitoral self-stimulation was used by healthy, young adult women volunteers (n = 28) to induce orgasm in the laboratory. The duration of the orgasm was obtained using the subject's verbal indication of its start and finish. The estimated duration and the subjective experience of the orgasm self-graded on a 5-point scale were also obtained in a number of subjects. Vaginal blood flow was assessed by the power consumption needed to keep a heated oxygen electrode, held on the vaginal wall by suction, at a constant temperature. The mean measured orgasm duration was 19.9 seconds (SD, +/- 12, n = 26). For 14 subjects, their estimate of the duration of their orgasms (12.2 +/- 9.8 seconds, mean +/- SD) was greatly underestimated compared with the measured duration (26 +/- 14.6 seconds). This result indicates that data obtained on the duration of orgasm from questionnaires or interviews have suspect validity. The measured duration of the orgasms was not significantly correlated with the subjective grading. The increase in vaginal blood flow at orgasm was not significantly correlated with the subjective gradings of orgasm (n = 18), the orgasm latency (time taken to induce orgasm, n = 18), or the measured duration of orgasm (n = 14).