Sound Power - Sound Power Measurement

Sound Power Measurement

A frequently used method of estimating the sound power level at a source is to measure the sound pressure level at some distance, and solve for :

L_\mathrm{W} = L_\mathrm{p}-10\, \log_{10}\left(\frac{1}{4\pi r^2}\right)\, If the source is in free space

or

L_\mathrm{W} = L_\mathrm{p}-10\, \log_{10}\left(\frac{2}{4\pi r^2}\right)\, if the source is on the floor or on a wall, such that it radiates into a half sphere.

The sound power estimated this does not diminish or increase with distance, unless reflections are present.

Read more about this topic:  Sound Power

Famous quotes containing the words sound, power and/or measurement:

    “There was a sound of revelry by night,
    And Belgium’s capital had gathered then
    Her beauty and her chivalry, and bright
    The lamps shone o’er fair women and brave men;
    A thousand hearts beat happily; and when
    Music arose with its voluptuous swell,
    Soft eyes looked love to eyes which spake again,
    And all went merry as a marriage-bell;
    But hush! hark! a deep sound strikes like a rising knell!”
    —George Gordon Noel Byron (1788–1824)

    “The dissident does not operate in the realm of genuine power at all. He is not seeking power. He has no desire for office and does not gather votes. He does not attempt to charm the public, he offers nothing and promises nothing. He can offer, if anything, only his own skin—and he offers it solely because he has no other way of affirming the truth he stands for. His actions simply articulate his dignity as a citizen, regardless of the cost.”
    —Václav Havel (b. 1936)

    “That’s the great danger of sectarian opinions, they always accept the formulas of past events as useful for the measurement of future events and they never are, if you have high standards of accuracy.”
    —John Dos Passos (1896–1970)