After a little experimentation when they started doing this I found the second button from the top on the right immediately mutes the audio. Since then I’ve verified this works at a lot of different gas stations on car trips across the US.
I'll second this. I have found some that use a different button but usually one of them cancels it so feel free to try them all. I think I've found only one that couldn't be at least muted in this way.
It used to work everywhere. Over the last 2 years, an increasing number of pumps have been modified so that this no longer works.
a few I've seen, some kind soul will have marked the mute button with a sharpie