Season five was the first season to not have an American born judge on the panel.
Howie Mandel has the longest tenure of serving as a judge on the show, thirteen seasons straight. Heidi Klum has served as a judge for the second longest amount of tenure, nine seasons, but was unavailable to be present for the fourteenth season.
Televised auditions have been always held in New York City and Los Angeles for the first ten seasons. Since Simon Cowell joined the judging panel in season 11, the auditions have always been held at the Pasadena Civic Auditorium, taped on multiple different days.
The sound made when the judges "check" an act was originally the sound used when spins are passed on "Press Your Luck". The sound made when the judges "X" an act is the strike sound used in "Family Feud".
Right before Piers Morgan left and Howard Stern joined, Stern was interviewed by Morgan on his talk-show, Episode #1.2 (2011). Stern had personally told Morgan that he actually enjoys him as a judge.