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Difference in sound pressure for 10 dB(A) change "A" weighted
----------------------------------------------------------------------------------- Sound pressure for 65 dB(A)
dB(A) = 20 * log[sound pressure/sound pressure at 0 dB(A)] 65 dB(A) = 20*log[sound pressure/20] 65/20 = log[sound pressure/20] 3.25 = log[sound pressure/20] 103.25 = sound pressure/20 1778.279*20 = sound pressure = 35566 micro pascals
----------------------------------------------------------------------------------- Sound pressure for 75 dB(A)
dB(A) = 20 * log[sound pressure/sound pressure at 0 dB{A)] 75 dB(A) = 20*log[sound pressure/20] 75/20 = log[sound pressure/20] 3.75 = log[sound pressure/20] 103.75 = sound pressure/20 5623.413*20 = sound pressure = 112468 micro pascals
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Sound pressure change = 75 to 65 dB(A) = 112468 -35566 = 76902 micro pascals
% decrease 75-65 = (76902/112468) * 100 = .6838* 100 = 68.38% decrease % increase 65-75 = (112468/35566) * 100 = 316% increase
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