The Decibel Scale Explained

The decibel (dB) is the unit of measurement that describes the intensity of sound. The human ear is tremendously sensitive, and the dB scale is designed to measure that sensitivity. However, the range in sound intensity is so great, the human ear can pick up the sound of a fingertip brushed over someone’s skin as well as incredibly loud engines.

To demonstrate the range, the noise produced by a jet engine is about 1,000,000,000,000 greater in power than the quietest audible noise.

Charts like this spread important information about the dangers of noise exposure,
but are misleading in their depiction of relative decibel levels. Source: webmd.com

dB Scale Increases as Sound Intensity Grows

In some ways, you can compare the dB scale to the Richter scale, which measures the intensity of earthquakes. The measurement levels increase almost exponentially. 10 dB is 10 times more intense than 0 dB. A sound that is 1,000 times more intense than 0 dB (near total silence) is 30 dB.

How Loud is Loud?

Some common dB measurements include near total silence at 0 dB, a normal voice is 60 dB, a rock concert is around 110 dB, while a firecracker is about 140 dB.

In addition, distance impacts the intensity of noise. The intensity diminishes with distance. Therefore, the dB scale takes into account the noise very close to the source.

What Sound Levels Cause Ear Damage?

Noise above 85 dB may result in hearing loss. This loss comes from both the intensity of the noise and the length of exposure to the noise. If you need to raise your voice to be heard, chances are that you are listening to sound at around 85 dB. Eight hours of exposure to higher levels at 90 dB can cause damage to your ears. Noise above 140 dB results in immediate, permanent damage and intense pain.