The plastic vuvuzela trumpet has been controversial since the Confederations Cup last year, a World Cup dress rehearsal, when several players complained they could not communicate through the din, which sounds like a herd of charging elephants.
FIFA President Sepp Blatter rejected calls for them to be banned, saying they are as typical of South African football as bongo drums or chants in other countries.
They will surely be one of the more memorable aspects of this, the first African edition of the football spectacular.
Journalists covering warm-up games have realised they cannot communicate by phone over the noise and that is before Johannesburg's Soccer City stadium fills up for the opening match on Friday with 90,000 people, many armed with trumpets.
Thailand manager Bryan Robson said after his team's drubbing in a friendly by South Africa last month that he could not communicate with his players on the pitch.
But to Spanish musicologist Pedro Espi-Sanchis, vuvuzelas can make music and the plastic instrument virtuosos must only be coordinated to make a pleasurable sound.
"On television all you can hear is those rhythms mixing into a grey drone of the B-flat and that's what millions of people will be hearing during this World Cup. That is really what hurt me as a musician ... that is not Africa," said Espi-Sanchis, 57, an expert on traditional music.
TRADITIONAL KUDU HORN
He told Reuters the vuvuzela was developed from the kudu horn, traditionally used to announce a ceremony or major event.
"Then somebody thought we can use this in the stadium and started mass producing them, and suddenly there were tens of thousands of those blooming things."
They were intended to scare the opposition, he says - something likely to appeal to South Africans, who as the world's 83rd ranked side, risk being the first tournament hosts eliminated in the first round.
South Africa manager Carlos Alberto Parreira, not surprisingly, thinks vuvuzelas are a great idea. "We have to try to reinforce that advantage. We want it louder and louder."
Espi-Sanchis says that if you are standing in a trumpet group in the stadium you can hear a rhythm.
"The problem here is that no one has tried to synchronise the whole stadium, all the vuvuzelas in one stadium to play the same rhythm. It is just a matter of will and a matter of saying just do it. If people in Europe can sing the same song in the stadiums we can play the same rhythm here," he said.
So he has created four vuvuzela orchestras, three in South Africa and one, bizarrely, in Vienna.
He tunes seven vuvuzelas to play chords by cutting them to different lengths, then mixes them with a bass guitar, drums, trumpets or trombones and a singer.
One orchestra played at the opening of Cape Town's graceful new Green Point stadium earlier this year and they have also performed at half time in domestic football matches.
