Noise
Fans generate noise from the rapid flow of air around blades and obstacles, and sometimes from the motor. Fan noise has been found to be roughly proportional to the fifth power of fan speed; halving speed reduces noise by about 15dB.
Read more about this topic: Mechanical Fan
Famous quotes containing the word noise:
“Sing unto the Lordwith the harp, with the harp, and the voice of a
psalm.
With trumpets and sound of cornet make a joyful noise before the Lord,”
—Bible: Hebrew Psalm XCVIII (l. XCVIII, 5–6)
“You may say a cat uses good grammar. Well, a cat does—but you let a cat get excited once; you let a cat get to pulling fur with another cat on a shed, nights, and you’ll hear grammar that will give you the lockjaw. Ignorant people think it’s the noise which fighting cats make that is so aggravating, but it ain’t so; it’s the sickening grammar they use.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“But what it was, alas, I cannot tell,
Because of it I had no perfect view;
But as it was, by guess, I wish it well
And will until I see the same anew.
Shadow, or she, or both, or choose you whither:
Blest be the thing that brought the shadow hither.”
—Unknown. I Heard a Noise and Wishèd for a Sight (l. 13–18)