Some things always keep changing, like how YouTube has been doing for some time now. YouTube has recently (some months back actually) redesigned it’s interface and we are getting used to it.
YouTube is good at playing some pranks too ! After April 1 fools day prank (Textp), it seem we have another one here, this time it is 2010 FFIA World cup special, the “Vuvuzela” effect to the audio.
Have you noticed the small football icon 
while watching some of the YouTube videos off-late? Just go ahead and click on it, surprise !! who’s blowing the “Vuvuzela” there ?
The annoying Vuvuzela sound toggles on and off if you click this football icon. Although this button can’t been found on all videos, it’s indeed showing up on some non-soccer videos on the YouTube.