Hello all, probably a very basic question but I'd appreciate the help. If a ultrasound frequency swept signal has increased density and voltage in a biological object does that mean that the object's naturally-occurring singal frequency has also been increased?

 

The source of the ultrasound is not likely to see a variation on the output due to being aimed at a region of greater density in the subject.

The voltage used to operate the ultrasonic probe is neither affected by nor transfers to the biological specimen. The ultrasonic signal has several characteristics, but density is not one of them. Density is confined to the material being probed.

Sound travels at different speeds in mediums with differing density, a phenomenon used by geologists when using sound to map underground structures. That implies that a denser material passes sound faster than a softer one. It is unlikely that a natural frequency exists in the various materials. If that were the case, all one would have to do is listen, rather than have to use a probe to couple a frequency into the subject.

It is entirely possible that the ultrasonic signal is chirped (changed in frequency) in order to elicit more information. The biological subject is passive in all this. Sound waves simply traverse the material and get reflected back to the probe for analysis.