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:
“I am already kindly disposed towards you. My friendship it is not in my power to give: this is a gift which no man can make, it is not in our own power: a sound and healthy friendship is the growth of time and circumstance, it will spring up and thrive like a wildflower when these favour, and when they do not, it is in vain to look for it.”
—William Wordsworth (1770–1850)
“Pushkin’s composition is first of all and above all a phenomenon of style, and it is from this flowered rim that I have surveyed its seep of Arcadian country, the serpentine gleam of its imported brooks, the miniature blizzards imprisoned in round crystal, and the many-hued levels of literary parody blending in the melting distance.”
—Vladimir Nabokov (1899–1977)