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:
“It is with unfathomable love, pure joy and no regret that we leave this world. Men, do not cry for our fate, but cry for your own.”
—Members of the Order of the Solar T.. New York Times, p. 1 (October l4, 1994)
“It hurts me to hear the tone in which the poor are condemned as “shiftless,” or “having a pauper spirit,” just as it would if a crowd mocked at a child for its weakness, or laughed at a lame man because he could not run, or a blind man because he stumbled.”
—Albion Fellows Bacon (1865–1933)