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:
“Like most vigorous-minded men, seeing that there was no stopping-place between dogma and negation, he preferred to accept dogma. Of all weaknesses he most disliked timed and half-hearted faith. He would rather have jumped at once to Strong’s pure denial, than yield an inch to the argument that a mystery was to be paltered with because it could not be explained.”
—Henry Brooks Adams (1838–1918)
“Genius resembles a bell; in order to ring it must be suspended into pure air, and when a foreign body touches it, its joyful tone is silenced.”
—Franz Grillparzer (1791–1872)