Uh, are you sure of what you are writing here? Time-frequency analysis (including spectrograms) is one of the very fundamental tools for signal processing.
I was mainly responding to the OP's distinction between analyzing a visual representation and analyzing a "2d array" when they are basically the same thing.
This is what I mean. I guess their tooling just outputs graphics and it's easier to work with those than the pure 2d array in numpy or something similar.