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 old coat that I wear is Concord; it is my morning robe and study gown, my working dress and suit of ceremony, and my nightgown after all. Cleave to the simplest ever. Home,—home,—home. Cars sound like cares to me.”
—Henry David Thoreau (1817–1862)
“The word which gives the key to the national vice is waste. And people who are wasteful are not wise, neither can they remain young and vigorous. In order to transmute energy to higher and more subtle levels one must first conserve it.”
—Henry Miller (1891–1980)