Background: The auditory, olfactory and taste thresholds get modified by changes in gonadal function. Auditory brainstem responses vary with age and sex of the individual. Auditory acquity also varies with the phase of menstrual cycle.
Aims & Objective: To study the effects of cyclical changes of endogenous sex hormones in different phases of menstrual cycle on Brainstem Auditory Evoked Responses.
Materials and Methods: The brainstem auditory conduction (BAEPs) recording was done in normal 40 healthy regular menstruating females in age group 19-23 years during three phases of same menstrual cycle. Phase 1:1-3 days with lowest level of oestrogen and progesterone, Phase 2:11-14 days with peak level of β-oestradiol and Phase 3:17-23 days with peak level of progesterone. Absolute latencies of I, III & V waves and interpeak latencies (IPL) of waves I-III, I-V and III-V were recorded in three phases of menstrual cycle and compared statistically.
Results: The comparison showed a statistically significant increase in absolute latencies of I, III & V waves in phase 2 compared to phase 1 and a statistical significant decrease in their values in Phase 3 compared to Phase 2. However, the variation in interpeak latencies I-III, I-V and III-V showed insignificant variation.
Conclusion: The study showed that variation of hormones during menstrual cycle affect the central auditory conductivity in young rural females.
Key words: Absolute Latencies; IPL; 17-β-Oestradiol; BAEP