Galtonpfelfe Galton whistle for testing acuity of hearing made, with modifications, by Edelmann of Munchen. Whistle is in original box, the rubber air hose is missing. The Galton whistle, invented by Sir Frances Galton (1822-1911), was one of the earliest devices used in testing hearing. M. T. Edelmann improved the Galton whistle in 1900, after which it was sometimes known as the Edelmann Galton whistle. It was used in the first quarter of the 20th century, but was later abandoned when better instruments were introduced, including the audiometer. To use the Edelmann Galton whistle, air is blown into the nozzle at the right end and emerges from a circular slit (center right) to fall on the knife edge (center left). The size of the chamber to the left of the knife can be controlled by the piston in the left micrometer. The frequency of the sound emitted depends on the size of the chamber to the left of the knife edge and the pressure at which the air enters the nozzle. 1900-1949