Denoise is a constant battle. Know the enemy and repair your noisy audio tracks!

A common secret in the post production world is the following: "the outcome of an engineer's effort to remove noise from audio tracks is directly related to the time-frequency characteristics of the noise sources". So we prepared a "noisy" quiz for you: can you identify noise sources from their spectrograms? Take the quiz and see if you will be available to identify the worst enemies of everyone who deals with audio restoration!