2020 and I've still never heard this, but have heard lots of beeping on even new trucks. The vehicle standards in Australia are not prescriptive on the matter apart from "intermittent audible signal on a regular time cycle.  It must not emit a signal louder than is necessary to warn persons of the proximity of the reversing vehicle."<br>If I did hear this white noise, particularly near a construction site, I'd assume someone was using some sort of air compression tool and wouldn't give it a second thought. The regular cycling of the sound would likely have to continue for a while before I consciously noted it as oddly so. I would therefore agree with others here, a warning signal is typically most useful when people understand it's a warning signal; otherwise it's only a theoretically effective warning signal.,(reply>), @Zoravar .K Fair enough, I imagine YT's compression doesn't do it justice; however the point remains that it's only an improvement if people understand that it is a warning signal. <br>Probably best paired with some sort of education program if manufacturers in a country transition to using it.,(reply>), When you hear it it really sticks out. Doesn't sound like air systems at all. The sound just doesn't taper. Those sound designers know what they're doing.