A supporter of South Africa blows his vuvuzela during a training session of Germany's national soccer team in Pretoria June 7, 2010. The 2010 FIFA Soccer World Cup kicks off on June 11. [Agencies]

JOHANNESBURG - There will be no curbing of South Africa's raucous vuvuzela fan trumpets during the World Cup despite earlier concerns their din could drown out emergency announcements.

Chief Local Organiser Danny Jordaan said that officials tested noise levels at the refurbished 90,000 seat Soccer City stadium in Johannesburg when it was almost full for the first time during a friendly between South Africa and Colombia.

He had said there were concerns the trumpets, which sound like a herd of charging elephants, could drown out emergency announcements or be disrespectful during the playing of national anthems.

Following the tests, Jordaan said: "Now the vuvuzela is in this World Cup. It is part of this World Cup."

FIFA President Sepp Blatter has also defended the trumpets, saying they are as much a part of soccer in South Africa as bongo drums or chanting in other nations.

Jordaan said fans would be asked not to blow the plastic trumpets during the national anthems but there would be no bans.

During last year's Confederations Cup, a dress rehearsal for this month's soccer spectacular, foreign players and managers complained about the din.

Thailand manager Bryan Robson said during a friendly against South Africa last month that he was unable to communicate with his players because of the trumpets, which he said could give South Africa an advantage during the World Cup.