Could I stand next to a helicopter with a sufficiently big and well calibrated speaker and not hear a thing? (assuming I have one ear... I guess you can't cancel for two points at a time?)

We make houses out of solid brick, or brick that, while hollow, you can't pass wires through. The wall is built, then a channel for the plastic conduit is carved into it.

This is standard: https://i.imgur.com/rZdWBD9.png

Ah, ok, you mean underground ones. We use conduits in the wall, either metal tubes, or plastic corrugated conduit, I thought you meant those.

I live in Argentina. What makes them safer?

What do you use if not conduits? We use them here

So you guys use solid wires? They have not been used where I live for decades... Only very old cables are still solid, the kind wrapped in cloth