Drinking cranberry juice is a fairly well-known and natural way to both help prevent urinary tract infections, as well as help speed the recovery process when a UTI develops. Just drinking two 4-ounce glasses of cranberry juice daily is often enough to both prevent a UTI and speed recovery when an infection does develop.
Ultrasound waves travel faster through a stiff medium, such as bone. In echocardiography, the velocity of sound is assumed to be approximately 1,540 m/sec (or 1.54 m/msec). Sound waves travel through the air with speed of 330 m/s.
Ultrasound is cyclic mechanical vibration with a frequency greater than the upper limit of human hearing, which is approximately 25 kilohertz (25,000 hertz) in healthy, young adults. A vibration source in a mechanical medium will cause wave propagation. Ultrasound is a mechanical wave, cannot exist in vacuum.