Mine is a week 35. I called Apple yesterday to complain about the hiss during video recordings. Also when I first got home and I plugged it into my laptop to restore a backup, it chirped and hissed and buzzed quite loudly. But hasn't done that since. If I put it to my ear I can hear it though.
My dual camera lens already has a scratch in it too, despite the fact I treat it with kid gloves. Always goes in my front left pocket, no keys or coins kept in that pocket. Just the phone.
I asked for an express replacement sent to my house but they refused as the phone is so new (??). It's a huge pain in the ass to get to my city's one and only Apple Store, genius bar appointments are always booked out almost 2 weeks in advance. They suggested I go to an authorised repairer to get it checked out. Also inconvenient as I work long hours.
I just want a replacement phone and I don't want to have to jump through a bunch of hoops to get one.
I also went to the store where I bought it, my phone carrier's retail store. Even though the phone is only 7 days old, they said they would send it away for repair instead of replacing it. What a crock!