In France I see (and hear) more and more use of a special type of warning device, "le cri de lynx" that reduces sonic pollution by building sites.

Sadly I don’t speak French and Searching for whatever this is isn’t working.

If it’s noise cancelling it sounds amazing.

Can you further expand?

It's the noise you hear at about the one minute mark when the digger is reversing: https://youtu.be/BljL3XO0fyg?t=59

Oh this is horrible.

We don’t want people run over by reversing vehicles, but also, if I had to listen to that every day, I’d leap in front of them.

	▲	slobotron 3 hours ago \| parent [-]
		IMO, in person it's much nicer on the ears than the old single-tone beep that they used to have. It's less jarring and easier to locate where the noise is coming from, ye olde beep seemed to come from everywhere at once.