To determine the precision of a new ultrasound device and to establish a reference curve for normal French females, amplitude-dependent speed of sound (AD-SoS, m/sec) was measured using a DBM Sonic 1200 device (IGEA, Carpi) at four proximal phalanges of the nondominant hand in healthy women. In vitro precision from 21 measurements of a plexiglass phantom was 0.3%. In vivo short-term precision was 0.84% +/- 0.48% in 15 younger adults (age 31 +/- 10 years) and 0.81% +/- 0.038% in 15 older adults (age 62 +/- 16 years). Interobserver coefficient of variation was 0.77%. One hundred twenty-eight healthy female hospital staff members or friends of hospital staff members were studied (age 51.2 +/- 17.4 years). AD-SoS decreased by 9.6% between 30 and 80 years of age. Separate analyses of pre and postmenopausal women and of ten-year age groups demonstrated that AD-SoS remained unchanged before menopause but decreased by 7.6% after menopause (age 64.14 +/- 7.5 years; range 41-80). These data from normal females were compared with those reported by others in females and males. Age at menarche apparently influenced AD-SoS in later life. Reproducibility of the device used for this study was acceptable. Our cross-sectional data suggest that AD-SoS measurement is effective for detecting postmenopausal bone loss. Further investigations in osteoporosis are warranted.