H. J. L. Struycken was a Dutch otolaryngologist, phonetician, and acoustician. After studying medicine in Groningen, in 1893 he started working at the Voorburg psychiatric hospital near Vught, where he attempted to distinguish psychiatric conditions from neurological speech disorders. His interest in phonetics and acoustics took Struycken to France and Germany, to visit clinics and approach instrument makers who could produce tuning forks for him to use in his clinical research.
Fondazione Scienza e Tecnica,. (17 August 2015AD) 2015. “Sounds, Vibrations, And Marloye's Harp”. Florence, Italy: Fondazione Scienza e Tecnica. https://www.youtube.com/watch?v=Dro3_nwwUcI&list=PLslExxbg3O-fAeclmcjO0LId_xADwxalv&index=5.
Fondazione Scienza e Tecnica,. (17 August 2015AD) 2015. “Lissajous’s Figures, Wheatstone Apparatus For Compounding Two Orthogonal Oscillations”. Florence, Italy: Fondazione Scienza e Tecnica. https://www.youtube.com/watch?v=xPjNPb8h8Ok.
Franz Max Osswald, born in Winterthur, graduated as a mechanical engineer in 1905 at the Swiss Federal Institute of Technology (E.T.H.). In 1924, he installed a laboratory for applied acoustics at E.T.H. After completing his habilitation in 1928, he served as the first acoustician at a polytechnic, teaching as a "Privatdozent." Osswald described his discipline as an indispensable complement to architecture, technology, and hygiene.