Question

The loudness, L, measured in decibels (Db), of a sound intensity, I, measured in watts per square meter, is defined as L = 10 log StartFraction I Over I 0 EndFraction, where I 0 = 10 Superscript negative 12 and is the least intense sound a human ear can hear. What is the approximate loudness of a dinner conversation with a sound intensity of 10–7?
–58 Db
–50 Db
9 Db
50 Db

Answer 1

I = 10⁻⁷, I₀ = 10⁻¹² → I/I₀ = 10⁵.
L = 10 log(10⁵) = 10·5 = 50 dB.

Answer: 50 Db.