Object, Instrument, Technology

See also Tuning fork

Picture: Max Planck Institute for the History of Science

Image
“Tuning Fork Collection Ii, Detail 1”. n.d. Berlin.
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.

Image
“Tuning Fork Collection Ii, Detail 6”. n.d. Berlin.
Object, Instrument, Technology

See also Tuning fork

Picture: Max Planck Institute for the History of Science

Object, Instrument, Technology

Invented by John Shore in 1711, the tuning fork was initially used by musicians. After Chladni’s studies of its vibrations, however, it was also extensively employed by acousticians, who praised the purity of its sound. Hermann von Helmholtz, especially, based his experiments with beats, combination tones, and simple tones on tuning forks attached to resonators that enhanced their suitability for experimentation.

Object, Instrument, Technology

Source: Deutsches Museum, Munich (https://digital.deutsches-museum.de/item/4423/)

Object, Instrument, Technology

This rack has 3 square and 3 circular brass plates of varying dimensions. It was used to demonstrate the effect of changes in the size and thickness of plates on both their tone and the Chladni figures that they produce. A plate that is the same size as the one next to it, but double the thickness, will produce a note twice as high, while a plate that is half the area of the one next to it, but double the thickness, will sound a note that is four times higher.

 

 

Object, Instrument, Technology

Picture: Max Planck Institute for the History of Science

Object, Instrument, Technology

This set of resonance bars, each with its’ own resonator, can be used in an interesting demonstration. First, because the bars are physically identical, they both have the same resonant frequency. And that sound is strongly amplified by the wooden resonators on which the bars are mounted. In the demonstration, the two instruments are placed some distance apart and the first bar is struck sharply to make a tone. Because the two bars are identical, the second bar will respond to the sound of the first by making the same tone.