Question #af8bf
1 Answer
We use the decibel scale to measure relative loudness. See details below.
Explanation:
Difference in loudness is very much a subjective observation, meaning it is difficult to define it precisely or attach it strongly to a characteristic of the wave itself. Generally it is linked to the power transmitted by the wave per square metre of surface area.
If one wave transmits 10x the power of another, we use a logarithmic scale to compare the loudness, and say that one is louder by one Bel. (100 times louder = 2 Bels, 1000 times = 3 Bels, and so on.)
Then, to create a finer scale, we divide the Bels into tenths and say the louder sound is greater by 10 decibels (10 dB), if it carries 10 times the power.
20 decibels is 100x as much power, 30 dB is 1000x as much power, etc.
