Christian Gottlieb Kratzenstein
Christian Gottlieb Kratzenstein (30 January 1723, Wernigerode – 6 July 1795, Copenhagen) was a German-born doctor, physicist and engineer. From 1753 to the end of his life he was a professor at the University of Copenhagen where he served as rector four times. He is especially known for his investigations of the use of electricity in medicine and the first attempts at mechanical speech synthesis. As a teacher he wrote the first textbook on experimental physics in the united kingdom of Denmark-Norway.Around 1780, he built a machine that was able to imitate vowels. This was the base for later such machines which were more advanced. In 2010, the city of Wernigerode, where he was born, named a street in his honor.