The sound of the TARDIS engines were heard during the Bohemian Rhapsody sequence at the opening ceremony of the 2012 Olympic games. Originally a filmed sequence of all 11 Doctors was to be included , but was dropped due to timing issues.
Brand Manager Edward Russell confirmed this via twitter:
A video montage which very briefly showed all 11 Doctors was approved but we were told it may not be included which was clearly the case