Ditto verizon over att. We have had repeatedly problems with signal on AT&T, especially on beaches and inside certain dwellings. One cell phone has been switched to Verizon and immediately the signal problems vanished.
Now I'm off to find Beach Runner's phone case on google because we had the same sound problem and my Lifeproof case ultimately failed on the beach one day too. Mailed it in and they covered replacement of the case under warranty as defective, but they don't guarantee the product to not damage the phone - we didn't realize their warranty was limited to replacement of the actual case and not a damaged phone when the case is defective - lesson learned!
Now I'm off to find Beach Runner's phone case on google because we had the same sound problem and my Lifeproof case ultimately failed on the beach one day too. Mailed it in and they covered replacement of the case under warranty as defective, but they don't guarantee the product to not damage the phone - we didn't realize their warranty was limited to replacement of the actual case and not a damaged phone when the case is defective - lesson learned!