Turn on your TV right now to whichever sports channel is showing the England's soccer game against the USA in the World Cup in South Africa. Turn the sound up. Why does it sound as if several dozen propeller-drived airplanes have started up their engines in the stadium? Has someone dropped one of the commentator's mikes into a huge beehive? No. It's just that South Africans love to bring annoying three-foot-long one-note plastic trumpets to every game and blow them continuously. (They all seem to be tuned roughly to A below middle C.) [Geoff Pullum in Language Log].
Harry Campbell draws my attention to the claim reported in the media.
A vuvuzela is tuned - to use the term loosely - at the B flat below middle C, and has a similar frequency to speech tones, says Trevor Cox, president of the Institute of Acoustics. This makes it particularly tricky for broadcasters to tune out, as to do so would dampen the commentators' voices - and not in a good way.
"I'm looking at its wave patterns and there are at least six very strong harmonics in there. It would sound really horrible to notch these out - if one coincides with the vowel sound e, you won't be able to hear the -es in the commentary. It would sound unnatural."
Er, well, yes. I’m not going to start messing around with spectrograms myself, but it is obvious that the vuvuzela racket covers quite a range of frequencies. It is not a ‘pure tone’ like a whistle, which would have a single frequency that one might filter out.
The fundamental note is reportedly “roughly [at] A below middle C” or “at the B flat below middle C” (accounts vary, as you see). Let’s say 230 Hz or thereabouts. That would imply harmonics (overtones) at integer multiples of that frequency: 460 Hz, 690 Hz, 920 Hz etc. This coincides with the range of vowel first formants (not just e, all vowels), which is approximately 250–1000 Hz. So if you filter out the vuvuzela noise, you’re going to lose information that could be important in keeping speech intelligible.
Nevertheless, here is a plugin that claims to do that. Feel free to try it.
I think a better way would be for broadcasters to separate the commentary feed from the crowd noise feed, and to suppress all or most of the latter. Except for people who like the noise of the vuvuzela.