You can inspire others through stirring words or music. To do so, you use a Bonus Action on your turn to choose one creature other than yourself within 60 feet of you who can hear you. That creature gains one Bardic Inspiration die, a d6.
Once within the next 10 minutes, the creature can roll the die and add the number rolled to one ability check, Attack roll, or saving throw it makes. The creature can wait until after it rolls the d20 before deciding to use the Bardic Inspiration die, but must decide before the DM says whether the roll succeeds or fails. Once the Bardic Inspiration die is rolled, it is lost. A creature can have only one Bardic Inspiration die at a time.
My question is quite simple: How does this work with Passive Perception?
Firstly since Passive Perception is an ability check I assume it is a valid use of Bardic Inspiration, but I have read many different interpretations on Passive Perception on here; including DM's doing it slyly, even pretending to make checks to keep people off guard.
Passive Perception is 'always on' so how would you handle this? Do you just add 3 (The rounded up average for the d6) to the check for 10 mins?