Ultrasound is, by definition, sound above our hearing range. The reflected sound from moving blood is changed , and the amount of change is related to the direction and speed of the blood. This change in sound is within the range of our hearing. We can listen to this sound, or display it on a screen, and detect problems in how blood is flowing. If you have one of our studies, it will be likely that you will hear some of these sounds during the exam.
Arteries sound like a heart beat, since the heart is pumping the blood through the artery.
Flow in veins usually varies somewhat with breathing, and sounds more like a windstorm. We also utilize ultrasound to generate an image of the anatomy, and this assists us in evaluating the vessels with Doppler ultrasound. Muscle, blood vessels, and bone all reflect ultrasound differently. If the tissue is not moving, the reflected sound is not changed, but the amount of sound reflected varies. These variations are used to make the image.