A decibel is a unit that measures how loud a sound is. Scientists and engineers use decibels (abbreviated dB) to put precise numbers on noise levels, from the quietest whisper to the roar of a jet engine.

Here's how the scale works: normal conversation happens around 60 decibels, a vacuum cleaner runs at about 70 decibels, and a rock concert can reach 110 decibels or more. Every increase of 10 decibels makes a sound seem about twice as loud to your ears. So 80 decibels doesn't sound just a little louder than 70 decibels: it sounds much louder.

The decibel scale matters because sounds above certain levels can damage your hearing. Prolonged exposure to sounds above 85 decibels can harm the tiny, delicate structures inside your ears. That's why construction workers wear ear protection and why concert venues post warnings about noise levels.