WEBVTT
Kind: captions
Language: en-GB

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Behind these walls is Crossrail, or at least one of the sites for Crossrail.

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It's one of the largest engineering projects happening in the world right now.

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But I'm not here to talk about that, I'm here to talk about what it sounds like,

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because for decades now, every construction site in the world has had this noise.

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[beeps]

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Now obviously I've dubbed that in afterwards; it's a reversing beep, for I don't have a truck here ready to run me over.

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But in the last ten years or so, increasingly, you've been hearing a different noise instead.

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You've been hearing this:

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[loud hiss]

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a white noise reversing beep.

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And that came out of an invention at Leeds University in 2001.

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It's now become the standard for most major construction projects

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to the extent that Crossrail does not allow vehicles with an old-school single-tone reversing beeper to actually get in.

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So, why do I mention this? Because it's a fairly geeky fact to know.

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Well, two reasons.

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One is that it's safer.

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Your ears can pick out that broadband sound, that white noise, a lot better than they can pick out beeping.

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Which means that you can play it at a lesser volume, not annoy the residents around here as much, and it's safer

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because your ears can pick out that tone and tell where it comes from.

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A single monotone beep can do all sorts of echo things,

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it's not a natural sound, your ears aren't trained for it,

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but white noise, that kind of *pssh pssh pssh*, your brain can pick out where it's from.

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So if you've got five trucks in there, all reversing, you'll know where they are.

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And you'll know if one is about to run you over.

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And that is something you might not have known.

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