How to customize Facebook chat notification sound? Facebook app and the Facebook Messenger app often plays the same sound for new incoming chat message - this is the system notification sound.

That makes me confused facebook chat with other notification, especially the calendar reminder, new incoming email, etc. ...

How to customize it?
In Facebook, you can change the notification sound from Facebook > Menu > Settings > Notification ringtone.

I assume it would be the same for Messenger, never used it though