Object, Instrument, Technology

William Stern invented the tone variator in 1897 to study human sensitivity to changes in pitch, going beyond the traditional psychological research of studying the sensitivity to differences in discrete tones. The instrument consists of an adjustable brass resonator (see Helmholtz resonator for more information), which is supplied with a constant flow of air across an opening at the top.

Armstrong Cork,. 1932. “Armstrong's Acoustical Products”. Corkoustic, Ceramacoustic For Acoustical Correction Of Churches, Auditoriums, And Theatres, And Noise-Quieting Of Banks, Schools, Hospitals, Offices, Sunday School Rooms, Factories, And Other Public Buildings. Lancaster, PA.
Armstrong Cork,. n.d. “Reducing Vibration And Noise”. Nonpareil Cork Machinery Isolation For Reducing The Noise And Vibration Of Fans, Motors, Printing Presses And Machinery Generally. Pittsburgh, PA.
Armstrong Cork,. n.d. “Armstrong's Vibracork For Lessening Transmission Of Vibration”.
Contributor essay
David Pantalony; Erich Weidenhammer; Victoria Fisher

The University of Toronto acoustics collection consists of a comprehensive series of instruments made in the Parisian workshop of Rudolph Koenig (1832