The ancient history of ultrasound started in the 18th century, and after a slow start, it had a steep trajectory of rapid growth from the 1950s. It is still on that trajectory these days and there are multiple new developments presented each year. Besides the thousands of researchers working on the development of ultrasound devices, we have to thank an animal species, which uses ultrasound as navigation and was studied first at the end of the 18th century by the Italian biologist Lazaro Spallanzani. The road to medical applications led from the first animal studies through military and industrial advancements. Despite the initial scepticism from their peers the developments of the researchers leading the technical advancements have stood the test of time and have contributed to the evolution of a basic method in modern medical imaging.  Kulcsszavak: ultrahang történet, ekholokáció, szonár, Doppler, B-mód