Who'd have guessed that the Soccer World Cup would become a vehicle for millions of people - fans and non-fans alike - to learn more about audio acoustics and processing? But it has, thanks to the controversy over a loud and raucous African blowing horn - called a vuvuzela - used often and enthusiastically by thousands of spectators at the games to express support for their teams.
The problem is that not everyone's a vuvuzela fan. Announcers at the games and players on the field have complained that the noise interferes with their activity, while other spectators at the games have expressed concerns over possible hearing damage. And fans around the world watching on TV have been annoyed both by the loudness of the sound on the broadcasts, and by the degree to which it interferes with the clarity of the audio commentary.
The resulting attention to this issue has been enormous. It's produced a slew of news reports describing the acoustic characteristics of the vuvuzela, myriad solutions and how-to videos for "de-vuvuzelating" the sound on your TV, and even a hilarious new Downfall meme video ("Hitler and the vuvuzela at the 2010 FIFA World Cup").
The instrument at the root of all this is about 2 ft in length and made of plastic. It produces sound mainly at about 235 Hz and 465 Hz and is capable of sound pressure levels up to 130 dB. (Listen to the sound of a vuvuzela (4 s audio sample).)
Some of the offered solutions include vuvuzela noise reduction software plugins from commercial professional audio companies like Prosoniq and Waves. Others are simple DIY audio filtering solutions - typically using notch filters - that anyone can use on their PCs. Just a few of the examples of the latter include the following how-to YouTube videos:
The audio engineering behind the filtering solution presented in the last video is even described in an article at Physorg (How audio engineering helps tone down vuvuzela disruption). Finally, there's even a guide to vuvuzela fever for those who still wish to learn more about the instrument and various filtering solutions.
Comments, questions or suggestions? Email me at firstname.lastname@example.org.
Acoustics and Psychoacoustics Applied - Part 3: Filtering and equalization
Acoustics and Psychoacoustics: Introduction to sound - Part 1: Pressure waves and sound transmission | Part 2: Sound intensity, power and pressure level | Part 7: Analysis of sound waves | Part 8: Using filters to analyze frequency spectra