Slashdot Mirror
Digitally Filtering Out the Drone of the World Cup
qubezz writes "World Cup soccer fans may think a hornet's nest has infiltrated their TVs. However the buzz that is the background soundtrack of the South African-hosted games comes from tens of thousands of plastic horns called vuvuzelas, that are South Africa's version of ringing cowbells or throwing rats. It looks like the horns won't be banned anytime soon though. A savvy German hacker, 'Tube,' discovered that the horn sound can be effectively filtered out by applying a couple of digital notch filters to the audio at the frequencies the horn produces (another summary in English). Now it looks like even broadcasters like the the BBC and others are considering using such filters on their broadcasts."
The BBC themselves has an article up (http://news.bbc.co.uk/2/hi/uk_news/magazine/8738604.stm) about the ineffectiveness of this filter, the issues filtering out the noise of vuluzelas could cause for the coverage in general, and the rest of their own good reasons for NOT using this shim.
The role of the writer is not to say what we can all say, but what we are unable to say. -Anais Nin
I wrote up a blog post about using Sound eXchange (sox) to filter the sound here: http://www.russellbeattie.com/blog/linux-command-line-streaming-vuvuzela-filter , but the short version is this:
rec -d vol .5 equalizer 233 .1o -48 equalizer 466 .03o -48 equalizer 932 .02o -48 equalizer 1864 .2o -24 | play -d
or from a response to my post here: http://www.yusufk.za.net/?p=520
rec -d | play -d vol 0.9 bandreject 116.56 3.4q bandreject 233.12 3.4q bandreject 466.24 3.4q bandreject 932.48 3.4q bandreject 1864 3.4q
After testing, I feel the parameters could be tweaked a bit more - but these definitely make a difference.
-Russ
Me
An earlier poster wrote:
I've seen a lot of comments around the Internet insinuating that if you hate the sound of vuvuzelas, then you're a colonial racist who hates South African culture.
The funny thing is that the vuvuzelas are a recent introduction into South African culture. They are not only post-Colonial, they are post-Apartheid.
The maker of the horns admits that the prototype came from the USA... http://www.boogieblast.co.za/vuvuzela.htm
and this has been known in wider soccer circles for at least a year... http://www.footballiscominghome.net/the-hosts/the-vuvuzela/
and while the plastic horns have been around since the late 90s in South Africa... http://www.southafrica.info/2010/vuvuzela.htm
the current mass-producer only started up in 2001... http://www.vuvuzelas.com/about.html
Additionally, there's the blaringly obvious notion that the vuvuzela looks nothing like the kudu horn it allegedly comes from and looks everything like a cheap rip-off of the sort of long thin horns you see draped with flags playing fanfares when kings enter in films set in the middle ages, but I suppose it's expecting a lot for everyone to think critically. Last time I checked, kudu horns didn't have embouchures, either, which is what allows the plastic horn blowers to last all game.
Chess Boxing
This signature serves no purpose other than to help you see which posts were made by me.
The sound level of the instrument has been measured at 127 decibels contributing to football matches with dangerously high sound pressure levels for unprotected ears. A new model, however, announced on 14 June 2010, has a modified mouthpiece which is claimed to reduce the volume by 20 dB
I can't imagine them banning vuvus would have much of an impact on the game -- for example, the crowd noise itself would be almost equally effective at preventing the players from communicating
Actually, it is much worse than normal crowd noise - they have already shown that a vuduzela can generate 125dB from 1m. 40,000 of those things can most definitely cause a level of hearing damage that normal cheering cannot.
I was in one of the louder indoor arenas (the HP Pavilion in San Jose) when it got over 105dB in the NHL playoffs - that was enough to cause my eardrums to literally start clipping, and a bit of pain after a while. I couldn't imagine 125+ dB for almost 2 hours straight...
That would be true, were it not for the fact that, unlike most US sports, there aren't many ad breaks in a soccer game. Also, in the UK many of the games are on the BBC, and the BBC doesn't openly advertise -- there's no actual commercial breaks, and all its advertising is done unethically, through covert product placement -- since it's forbidden from advertising. Not that that stops them.
Or use the EQ on your TV if it has one or the EQ on your Surround sound.
He "discovered" something that most people have known for decades... using a notch filter takes out unwanted frequencies.
Wow! Just think what they could do with that when we discover radio!
P.S.: they were already doing this at the stadium on the crowd mics, they just wanted to leave it in for the "effect" but they already were notching it a little bit to reduce the impact.
Do not look at laser with remaining good eye.
I didn't expect anyone on Slashdot to trot out the old and tired "real football" line. Soccer is the real football. You know, the sport that is played with the feet and with a ball? You must have been thinking of handegg instead, that American sport where players play with the hands and an egg, instead of a ball?
http://pix.motivatedphotos.com/2009/2/2/633692057194761860-handegg.jpg
English translation
http://translate.google.com/translate?hl=en&sl=fi&tl=en&u=http://yle.fi/uutiset/kotimaa/2010/06/yle_on_jo_suodattanut_lahetyksista_vuvuzelan_torinaa_1762215.html%3Forigin%3Drss
Spectator sports are like watching a game of pong instead of playing it.
Isn't the first rule that you don't talk about it?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."