What Is A Decibel? Can 'Negative' Decibels Exist?

The decibel is used to measure sound levels. It is represented by dB and is widely used in signals, communication, and electronics. The term decibel can be used to express an absolute value or a change in value (+1 dB or -1 dB).

Decibels are similar to the Celsius scale in the sense that it sets 0 as the freezing point of water, which means that this scale measures the temperature of things in relation to the freezing point of water. Likewise, 0 dB is the threshold of human hearing, i.e., the faintest sound the human ear can hear without artificial help.

0 dB means that you are right at the threshold of human hearing. A positive dB means the sound is a few times louder than the threshold, while a negative dB implies that you are a few times softer than that threshold.