Not a concern for me for the next 38 days (given up FB for lent), but I know this is frustrating a lot of people, so here is how to turn them off:
Facebook just added sounds to its iOS app for things like tapping the tab sections and submitting a post. If you don’t need a sound to let you know you just tapped a button, here is how to shut em off.
[Thanks to @MacFixer for the link]
(Via Finer Things in Tech)