A pure tone is a tone with a sinusoidal waveform.
A sine wave is characterized by its frequency, the number of cycles per second—or its wavelength, the distance the waveform travels through its medium within a period—and the amplitude, the size of each cycle. A pure tone has the unique property that its waveshape and sound are changed only in amplitude and phase by linear acoustic systems.
A pure sine wave is an artificial sound. Hermann von Helmholtz is credited as the first creator of a sine wave with the 'Helmholtz siren', a mechanical device that sends compressed air through holes in a rotating plate. This is presumably the closest thing to a sine wave that was heard before the invention of electronic oscillators.
Sinewaves are generally uncomfortable to the ear, and may cause noise-induced hearing loss at lower volumes than other noises. Sound localization is often more difficult with sine waves than with other sounds; they seem to ‘fill the room’.
Read more about Pure Tone: Fourier Theorem
Famous quotes containing the words pure and/or tone:
“He gathers deeds
In the pure air, the agent
Of their factual excesses.”
—John Ashbery (b. 1927)
“...I ... believe that words can help us move or keep us paralyzed, and that our choices of language and verbal tone have something—a great deal—to do with how we live our lives and whom we end up speaking with and hearing; and that we can deflect words, by trivialization, of course, but also by ritualized respect, or we can let them enter our souls and mix with the juices of our minds.”
—Adrienne Rich (b. 1929)