I never had any issues with call quality on my iPhone 4 but with my 5s people I am calling often complain that they cant hear me or that I sound as though I am in a tunnel. It seems like a problem with the microphone...I have taken the phone out of the case but the problem persists. This is problematic as I often use my phone for work and could very well be the catalyst that prevents me from continuing with iPhone. Any ideas?Ca