The purpose of this study was to compare the speaking fundamental frequency, physiological vocal range, singing voice quality, and self-perceptions of the singing and speaking voice between two groups of girls ages 11 through 15 years, who were pre-menarcheal by 6 months and post-menarcheal by 10 months or more. Subjects were volunteers who attended a North Texas public school system. Each subject was examined by an otolaryngologist. Age, height, weight, a hearing screening, and information on music classes and/or private music lessons were obtained. The speaking fundamental frequency measure was obtained by having each subject speak for 30 seconds on a subject of choice and read a passage of approximately 100 syllables. The vocal range measure was obtained by having each subject begin at an arbitrary pitch and sing mah and moo up the scale as high as possible and mah and moo down the scale as low as possible. These four measures were repeated with the researcher giving visual gestures. For singing-voice quality, each subject sang "America" in the key of her choice and again in the key of F major. Each subjects singing voice was rated according to breathiness. Data regarding self-perceptions of the singing and speaking voice were obtained through a rating assessment of 10 questions and a conversation with each subject. There were no significant differences between the means of the pre-meanarcheal and post-menarcheal girls on speaking fundamental frequency, physiological vocal range, and singing-voice quality. But, more of the post-menarcheal girls exhibited lower speaking pitches, lower singing ranges, and increased breathiness in their singing voices than did the pre-menarcheal girls. Two questions of the perceptions rating assessment were significant, with the post-menarcheal girls citing higher incidences of vocal inconsistencies than the pre-menarcheal girls. The findings of the qualitative data analysis indicated that more post-menarcheal girls had an adequate vocabulary to describe various aspects of their singing and speaking voices than did the pre-menarcheal girls.