Confused about ultrasounds...

[David513]

Hello all,

I know that waves that leave an ultrasound probe come back after interacting with dense media like bone at a faster/higher velocity. However, I don't understand why this is. I thought reflected waves do not change their frequency or wavelength, so how could they get faster? I know that the waves, when refracting into bone, could become faster, but then how do these waves not slow down by the time they get back to the ultrasound probe if they re-enter the aqueous medium from whence they came?

In the infamous words of Homer Simpson, "Save me Jeebus!"

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[RH8448]

I'm pretty sure that it is the wavelength that changes directly with the change in velocity of the sound wave. c=yf velocity and wavelength will be directly proportional to each other. Frequency only changes when the observer or object producing sound moves (Dopplar Effect)