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:
““What I want is a strange conjunction with you—” he said quietly; “Mnot meeting and mingling;Myou are quite right:Mbut an equilibrium, a pure balance of two single beings:Mas the stars balance each other.””
—D.H. (David Herbert)
“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)