Video
2012. “Demonstration Acoustic Siren”. Smithsonian National Museum of American History. https://www.youtube.com/watch?v=Rs7CC4pdJeM.
Video
2012. “Rotator Siren”. Smithsonian Institution. https://www.youtube.com/watch?v=hzoelA3Pm8E.
Video
Fondazione Scienza e Tecnica,. (17 August 2015AD) 2015. “Demonstration Of A Disk Siren”. Florence, Italy: Fondazione Scienza e Tecnica. https://www.youtube.com/watch?v=9OHfQLtMWWc.
Person

A scientist, inventor, engineer, and innovator who is credited with patenting the first practical telephone.

 

Picture: CC0 | Wikimedia

1847
1922
Person

Georg von Békésy was a Hungarian-American biophysicist who worked on physiology of hearing.

After studying chemistry in Bern, in 1923 Békésy was awarded a PhD in physics at the University of Budapest. He entered the service of the Hungarian Post Office, where he worked at the research laboratory on problems of long-distance telephone transmission.

1899
1972
Video
University of Michigan,. (25 July 2014AD) 2014. “Siren Disk Demo – The Musical Scale”. Houghton, Michigan: Michigan Technological University. https://www.youtube.com/watch?v=Hpt2LWgGQwo.