FIFA to discuss future of fan trumpet
Blatter said football's governing body would discuss the matter with the organisers.
"It's a local sound and I don't know how it is possible to stop it," he said on Wednesday. "I always said that when we go to South Africa, it is Africa. It's not western Europe.
"It's noisy, it's energy, rhythm, music, dance, drums. This is Africa. We have to adapt a little."
Vuvuzelas, which have been given away free to fans, are a constant background to Confederations Cup games.
Spain midfielder Xabi Alonso said: "I think they should be banned. They make it very difficult for the players to communicate with each other and to concentrate.
"They are a distraction and do nothing for the atmosphere," he added after his team's 1-0 win over Iraq.
FIFA general secretary Jerome Valcke said last year the vuvuzela would not be banned unless it was used as a weapon by fighting fans.