The purpose of this study was to analyze resonance characteristics (nasality and nasalance values) during the menstrual cycle. Previous studies indicate changes in voice quality and nasal mucosa due to temporary falling estrogen levels in human females during their menstrual cycle. The present study compared the nasality and "nasalance scores" obtained on 15 healthy participants. The first assessment was done during the first 3 days of the menses and a second assessment was done during postmenstrual ovulation phases using Nasometer II software, and a perceptual nasal resonance assessment was done using Buffalo III Voice Profile. The results revealed significant increases in the nasalance values during the menstruation phase. The findings indicate that hormonal and other related changes occurring during menstruation leads to a significant change in the resonance characteristics of voice. (Contains 1 table.)