When you get a new phone or wipe your phone, do not re-install your apps from your backup. Contacts would be the only thing I would do. Download everything fresh from the Play store. Seems my girlfriends backup was corrupt.
Before wiping my phone, I took a straight pin and carefully but thoroughly cleaned the speaker. I'd tried cleaning it before with a cloth as suggested in this thread to no avail. After trying this second method, I can hear perfectly. Glad I tried it