After the wireless telegraph, the invention that made it possible to speak at a distance and hear the voice changed the history of humanity. Applying knowledge of electricity and magnetism, Antonio MEUCCI (1808-1889) and Alexander Graham BELL (1847-1922) carried out research on telephone prototypes, modulating the direct current, achieving variations corresponding to the sound when speaking. James Clerk MAXWELL, creator of the theory of the electromagnetic field, one of the most important scientists in the history of science, stated that the telephone was not that difficult to imagine…