Help A peep after an hour

[alkalidodo]

My friends,
Happy Christmas. Just reset my phone to default and noticed one frustrating noise "A peep" after roughly an hour and cannot locate from where. After the peep there is no pop up on top of the screen. Pls help.

 

[Harry2]

Could be a Facebook notification.

I think I read something about that in the forum a few weeks ago.

Harry