Sound Levels
In the case of sound levels, engine operation is of greatest impact with respect to mobile sources such as automobiles and trucks. Engine noise is a particularly large component of mobile source noise for vehicles operating at lower speeds, where aerodynamic and tire noise is less significant. Petrol and diesel engines are fitted with mufflers (silencers) to reduce noise.
Read more about this topic: Engine
Famous quotes containing the words sound and/or levels:
“The mastery of ones phonemes may be compared to the violinists mastery of fingering. The violin string lends itself to a continuous gradation of tones, but the musician learns the discrete intervals at which to stop the string in order to play the conventional notes. We sound our phonemes like poor violinists, approximating each time to a fancied norm, and we receive our neighbors renderings indulgently, mentally rectifying the more glaring inaccuracies.”
—W.V. Quine (b. 1908)
“When I turned into a parent, I experienced a real and total personality change that slowly shifted back to the normal me, yet has not completely vanished. I believe the two levels are now superimposed, with an additional sprinkling of mortality intimations.”
—Sonia Taitz (20th century)