Object, Instrument, Technology

Date of production: 1950s

Image
“Brüel & Kjær 2304 Level Recorder (1)”. n.d.
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“Brüel & Kjær 2304 Level Recorder (2)”. n.d.
Object, Instrument, Technology

„This instrument was used in an Ohio high school and probably dates from the late 19th or early 20th centuries. The replication of classic experiments was a common way to teach science at this time, and Chladni’s figures were considered to be both instructive and beautiful. 

Object, Instrument, Technology

See also Helmholtz resonator

Picture: Max Planck Institute for the History of Science

Object, Instrument, Technology

This is a set of 16 Helmholtz resonators. Made from sections of brass that were spun on a lathe, they are wonderfully light and easy to hold. Helmholtz designed them to demonstrate his theory that all vowel and musical sounds are composed of combinations of simple, pure notes (Helmholtz’s “Theory of Timbre”). He correctly observed that musical sounds, particularly the higher tones, are often perceived as a single mass of sound.

Object, Instrument, Technology

In 1894, Olaus Henrici (1840-1918) of London devised a harmonic analyzer for determining the fundamental and harmonic components of complex sound waves. It consists of multiple pulleys and glass spheres, called rolling-sphere integrators, connected to measuring dials. The image of a curve (for example, a phonodeik tracing of a sound wave) is placed under the device. The user moves a mechanical stylus along the curve’s path, tracing out the wave form.

Object, Instrument, Technology

This photograph shows a three-dimensional representation of sound using paper. The spectrum (frequencies from low to high) is represented by an arrangement of single strips of paper, with lower frequencies in the foreground. The changes in the spectrum over time are visible as variations in the profile of the paper strips, if read from left to right. Such paper models were used at the Technische Universität Berlin in the 1960s to represent the sounds of speech (phonetics) and music (acoustics).

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“Handmade Paper Waterfall Plot: Mississippi (1)”. n.d.
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“Handmade Paper Waterfall Plot: Beethoven’s 8Th Symphony (1)”. n.d.