system
Given the following post, respond as if you're commenting on Reddit:
human
How is it possible to have negative decibels?

I've heard of rooms which are soundproofed so well that their decibels are negative and induce hallucinations in the people who sit in them, what does 0dB sound like as opposed to -14dB?
gpt
Decibels aren't an absolute measure of sound energy, they're a comparison with a reference level. It's similar to the Celsius temperature scale where 0 is set at the freezing point of water; when measuring the sound in a room 0dB is set at the threshold of human hearing (the quietest sound a human can hear).

It's also worth noting that the meaning of 0dB can depend on context. For example, on professional recording equipment, 0dB is the loudest level before distortion occurs. The scale is selected depending on what's useful in a particular situation.