That's actually Foxy's pirate song :D I think Bonnie and Chica are silent, except you can hear something moaning in their suits when they're by your door.
I have to say it though, you are one of the few people who I can find who can actually give a cute/funny aspect to otherwise terrifying suits, while still making them recognizable. Well done.
Link
Scottieboy2020
Dum da de dum de dum da dum...
Isn't that Bonnie's sound effect to let you know he/she is coming?
Also... did Freddie go Emo or something? XD