Response to short-duration signals, pre- and postmenses, in subjects using oral contraceptives and subjects not using oral contraceptives.

Sixteen female subjects were studied to determine threshold change occurring during and postmenses at thresholds of 1 and 4 kHz for signal durations of 500, 20, and 2 msec. The results indicated that there was no significant difference (p less than 0.05) for the thresholds of 1 and 4 kHz at any duration over the three test times. However, there was a significant second degree trend present at 1 kHz for the 20-msec signal. A comparison was made between the thresholds obtained by nine subjects who were using an oral contraceptive and seven subjects who were not. A significant difference (p less than 0.05) between the groups was found at 4 kHz for the 2-msec signal duration in that the group using oral contraceptives obtained threshold at a lower intensity than did the group not using oral contraceptives.