Microsoft made a -23 decibel room, but how does that work exactly? Once something hits 0 decibels how exactly can we measure it getting more quiet than that?
In: 24
A decibel is a relative measure of the power of something. Relative means that it is compared to some reference. In the case of decibels, it’s expressed in a logarithmic scale — you don’t really need to know what a logartihmic scale is, but it means that 0 is where the power is the same as the reference (**not zero power**). 10 decibels is 10x as much power as the reference, 20 decibels is 100x as much power, 30 decibels is 1000x as much power, and so on. It also means -10 decibels is 1/10th as much power, -20 decibels is 1/100th as much power, -30 is 1/1000th as much power.
When we talk about sounds, the reference unit is 20 micropascals in air and 1 micropascal in water (it varies depending on the fluid). A “pascal” is a unit of pressure, and those values were selected as the the average amount of pressure change that a person with good hearing can detect.
-23 decibels, therefore, is an amount of pressure (specifically 10^((-23/10)) x 20 mpa = 0.1 micropascals, in air); anything below 0 dB, a typical human can’t hear.
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