The other line can't understand me when I talk on my iphone 5.

They say my voice is muffled. The only way they clearly hear me is if I put my mouth directly in front of the bottom of my phone.

Then, I can't hear them. The phone does not catch my voice when I have it up to my ear speaking normally. It's not the way I speak, it's the phone. It also has become very sensitive screen wise. My ear hits the mute button all the time.