Measuring Sound with Decibels

Sound intensity level helps measure how loud sound is. The human ear sends sound waves to the brain, and the brain turns those waves into hearing. The loudness of the surrounding environment affects whether a person can tell different sound sources apart.

The ear can detect a very wide range of s...

On average, human ears are sensitive to a sound of intensity 10⁻¹² watt per meter squared at a frequency of 1000 hertz and can perceive a range of sound up to 1 watt per meter squared. However, a sound of this intensity can cause severe pain.

To incorporate the massive range in SI units, the logarithmic scale is used to define ...