Sound heard when browsing to website

When I go to this page http://www.narcocorridos.net
hear a background sound, this is a virus or something? or normal?
 
this only happens to me on this page!
 
I have sp2 Windows Vista Home Premium 64-bit
 
and I have Norton Internet Security 2010
 
thank you very much beforehand.

 

[edit: changed subject to reflect thread topic]