The speaker at the top of the phone may have gotten wet or damaged, this would also make sense that your snap chat sound is not working its from the same speaker. If your still having problems with the speaker after putting a new in then replace the flex cable for the speaker, front camera. You could also try a reset on the phone but I doubt that will fix it but you can try...Do a hard reset. Hold power and the home button at the same time until the Apple logo appears. If this fixes it, great! If not you need those two items!!