People are blowing it incessantly.

You can hear it very clearly on different World Cup commentaries.

Ah, triumph the best of this, but I'll try and get a tone out of it.

Ah, like any other wind instrument that you actually think that you blow into the way it works is that you set up a resonance of air inside the column on.

That's that Residents of air that gives it the air moving back and forth rapidly inside the column at a particular frequency, which is set by the the length of the column Microphone laptop.

The microphone is being fed into a USB port here.

OK, so what?

What What we're gonna do now is we're gonna take one phrase.

This is Philip Moriarty, University of Nottingham, for 60 symbols.

This is Philip Moriarty University of noting for 60 cents.

Right?

So let's say that so here's fell, whose are keen amateur trombonist self described on what he's gonna do is play a note on the Vuvuzela.

What's better than I can?

321 Ah, uh, we're gonna do here is loaded In that sample of my speech, we're gonna look at the frequency Spectrum University of knocking him for 60 symbols.

So what we have here is a frequency spectrum off that free, as I said, and you can say that there are lots of lots of different peaks spread across.

This is going from 100 hurts after my tree kilohertz.

And those are the primary components off may be the primary frequencies in my voice.

We look at the River Zilla Ah, way.

So if we look at this frequency spectrum, you see that it actually difference quite substantially from the spectrum of my voice On what we see here, we've got tree very well defined peaks in this spectrum.

This one here we call the fundamental That's the lowest wavelength, the lowest frequency that can exist in our shoes.

And after about 220 Hertz.

And I know from the physics of that instrument that this without even measurement, that this would be 440 twice times to 20 and this would be six, right, about 660 tree times to 20.

So that's the fundamental what we call the second demonic on the third demonic now.

So what we're gonna do now is wait.

Field players that note I'm gonna train, say the exact same phrase I said before, These are very load instruments.

Or I might have to show quite a bit.

And then we're going to see if we can filter around the side of the river Zula from the sound of my voice.

Right.

Okay.

321 Ah, uh, that's the problem the commentators have with the marches in that you've got this incredible drone going on all the time in the background and you're trying to hear you try to make yourself heard above that drone on.

So that's where the television companies are Very, very interesting.

Trying to feel it arrived.

That drone from the sound of the voice I know what I'll do is I'll try and take your true just how we do that.

I just had the companies do it.

So let's lock load in that speech on vuvuzela sample again.

Let's play it out back roll.

You know What I'm gonna do now is I'm gonna filter out the's first tree harmonics so that one of roughly 2 24 40 on 6 60 let's hear what difference that makes to the sound.

So this is Moriarty University of nothing for 60 symbols.

So you can hear immediately that the sound of my voice with respect to the sound off the vuvuzela has come up.

It's clear or you can get a bit more definition.

But you can still hear the vuvuzela and the recent you can hear the vuvuzelas You well, you can see almost from here.

You can see that as well as these tree Very strong harmonics.

We have these other harmonics.

And in fact, if I blew up the scale here, you'd see that they're harmonics going all the way out here.

So let's try it again.

But this time, instead of doing just the three harmonics, let's do it harmonics and see what difference that makes.

This is University 67.

You can still hear it in the background and if I continue this process, we could get rid of more more than rivers L.

A.

But the problem is why we're getting rid of the Vuvuzela were also taking out bits of the frequency spectrum associated with my speech.

So you've got to draw this balance, this compromise, and that's why it's impossible to totally decouple those two.

Ah, what I've shown you with something called notch filtering And the reason is called Not filtering, is that we're taking little notches over the frequency spectrum.

Getting rid of those that's that's straight for this very simply, do.

Now there's a rather less reputable company has decided that what they're gonna do is they're going to supply our recording an MP three off vuvuzela sound that they argue, has been recorded.

So it's in anti fears and anti phase means that the peaks and the troughs off the waves line up.

So the idea is that you cancel out those waves.

This is just complete on order.

Nonsense.