a guitar for calculating noises, regarding their power, or perhaps the regularity of this oscillations.
An instrument for experimentally deciding and displaying the number of vibrations of a sonorous human body (as a string or tuning-fork) in a unit period.
In psychophysics, a musical instrument for creation of accurately graded intensities of sound. The simplest type of phonometer is the sound-pendulum (which see). In Wundt's gravity-phonometer, ivory balls tend to be fallen by electromagnetic releases from varying levels upon hard-wood plates.
A clockwork instrument swung in gimbals, making sure that its face is always horizontal, and on whose switch are specific markings indicating intervals of which a whistle or any other sign should-be built to announce the compass span of the vessel.