Comparison of transient and distortion-product otoacoustic emissions during the luteal and follicular phases of the menstrual cycle.

We conducted a study to examine cochlear activity in women with a naturally occurring menstrual cycle by measuring transient otoacoustic emissions (TOAEs) and distortion-product otoacoustic emissions (DPOAEs). Our study population was made up of 11 women aged 20 to 40 years (mean: 35.6) who were not taking a contraceptive medication or hormone therapy. Measurements of TOAEs and DPOAEs were made during both the follicular phase and the luteal phase of the menstrual cycle. We found no statistically significant difference in any of the TOAE amplitude values between the two phases. Although a sharp decrease at the 0.75 kHz frequency was seen in DPOAEs during both phases, none of the amplitude values in the tested frequencies were significantly different between the two phases. The absence of TOAE and DPOAE amplitude changes suggests that it is unnecessary to take into account the phase of the menstrual cycle when interpreting the results of otoacoustic emissions testing.