FOUND IT! How to get rid of these pesky waveform generation in PP: it's in the Prefs!
Turn off the Automatic audio waveform generation, right there.
Aaaaa! I have to remember to check the Prefs each and everytime, else beware the waveform generation will get you STUCK with a BLACK SCREEN until it's done with its deeds.
Premiere generating waveform... Taking forever... ... ... Whoa! This black screen really looks great Adobe! Especially when I cannot do anything with my edit when this is happening.
On large projects it can take a long %#&%^ time!!! And you can do NOTHING but stare at the empty screen while this happens.
So Close the damn Project, go to the Prefs and TURN THIS OFF! Unless you really really need the damn waveform display, which of course we often do. Then GO GET A COFFEE or JUST GO HOME and let it rip. You've been warned.
Adobe, we pay good money every month to get cutting edge software. It's 2018, can you make these bolts and nuts click and clank IN THE BACKGROUND!? Without interrupting our workflow? We need to edit, right now!