It's easy to forget how many skills and "heuristics" go into listening. I once read a scale of language proficiency that placed "Can converse over a poor phone connection" at a very high level. When a word is garbled or lost, you have to quickly think of all the possible words that could've fit the grammar and whatever sound you heard, consider them in the context, and choose one or two. Then the next part of the conversation should let you pick one. Then add the complication of not seeing body language.

I forget where I read this. I think it was from the US Department of State, but I can't find it now.

Previous experience with aviation radio comms helps a lot. Typical radio comms essentially follow a template, and it’s done in a way where you can safely approximate a LOT (…just not numbers). But the…phraseology if you will, can be approximated quite easily with experience.

Funnily enough, American ATC / pilots are, I find, a lot more frequently ‘fast and loose’ compared to other areas, even English-speaking ones. Countless recordings online of EALD pilots being befuddled by some self-identified hotshot air traffic controller using overly casual / sloppy language, sometimes resulting in near misses or worse.