Hello. I have had this problem with my GF's phone for a while now. This is very confusing. She had the Rant phone from sprint, but when ever I called HER, and only her, she would be quiet. (EVEN the ring would be quiet, was weird.) EVERYONE else, I could hear just fine, ringer was loud, voice was loud, all was good. She sent in her phone to see if it was broken and she got a blackberry as a loner, and I could hear her just fine, it was great. (they moved the number, so its the same number.) They said there was nothing wrong with the phone, so now she has her mothers HTC Droid Eris, on her moms phone number, AND IT IS QUIET again! Same thing, when I call, even the ring sound through my phone when I call her is quiet. Can barely hear her voice, or anything, my phone is on full loud (would be super loud with anybody else talking) and I have to smash it against my ear to hear her. What the heck is going on?? Is there a way to bump up her microphone settings? Is it some weird network problem that I need to call sprint about? Can they boost her volume? Thanks.