Chosen Solution
My volume is all the way up but I cannot hear facetime calls, videos, snapchat videos, only voice calls.. i have no idea what to do, i reset it and updated software and nothing.
There are 2 speakers on your phone. One is the earpiece speaker that you heard phone calls though and the other is the loudspeaker which handles the applications you listed. The good news is that the loudspeaker is pretty easy to replace. iPhone 5s Speaker Replacement