← Why Twelve Notes · Lesson 4 of 4
Loud is logarithmic
Sound level in decibels compares powers on a logarithmic scale: ten times the power is +10 dB, and doubling the power adds only about 3 dB.
Distance matters too. In the open, the sound spreads over a sphere, so twice as far away is a quarter of the power: about 6 dB quieter.
A speaker is turned up so its power is 100 times what it was. How many decibels louder?
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