how an ultrasound transducer works

The transducer converts a short duration electrical impulse signal into mechanical vibration of similarly short duration.
This mechanical vibration emits a high-frequency pressure wave, also referred to as the sound waves or ultrasound transmission. During an ultrasound examination, these sound waves are aimed into the body where they are either reflected or absorbed by tissue structures.
The reflected waves are returned to the transducer, now working in reverse, and are converted back into an electrical signal.
This reflection-based electronical signal is digitized and filtered to form a reconstructed ultrasound image.