A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture risk. The primary components of the device are a voltage generator, a transmitting transducer, a receiving transducer, and hardware and software for reception and processing of the received ultrasonic signal. Reclassified from class 3 pma to class 2 510(k) 892.1180 [docket no. Fda-2005-n-0346] reclassification of bone sonometers