Others can't hear me when the speaker is away from my face. Even 4 inches to read the screen, or against my ear but tilted facing up. Any position that un-covers the ear-speaker, will CUT our voice. It's not MY phone only. I tried other phones at the store which had the same problem. ( was offered as replacement, same issue ) The problem is your voice entering through more than one microphone. They didn't give me a solution, but the second Apple rep. I'm speaking with about this, on the phone right now, waiting for an "engineer" (or something like that), also agrees it's the noise canceling feature. That cool feature (noise canceling) depends on having two different sound feeds, and sounds coming through the secondary microphone (somewhere around the ear-speaker) that are NOT entering through the primary microphone (in the phone's bottom) will be considered noise, and so removed from the final sound sent to your listener. The minimalist design of Apple always depends on you doing the things as they tell you, and not having MANY options for everything. Just "do it like this" and it's easier to remember every time. The same minimal options on the noise canceling made Apple think "if you people want to speak away the phone, use the "speaker" option. Yeah, sounds tyrany, but there's a thin line against "minimalism". And it works: By touching "speaker" the noise canceling feature stops annoying and ALL the microphones (seems to be three of them) take your voice from any conceived position. I actually made a profesional-grade song recording with my previous iPhone that you couldn't tell the difference with the original singer's voice in the retail version. And it was just an iPhone 4 (probably one or two mics only) in a regular furnished room. That good those mics are. You can hear a mouse whispering in the other room through them. So now I have to wait until someone else calls me in the next 48hs. All the tests were done, and it seems putting the hand on the speaker (where the sensor and secondary mic are) makes your voice go out better, since the intended requirements are met: your voice sounds louder through the lower mic. The noise canceling should kick in only when the phone is AGAINS the face (proximity sensor). The sensor IS THERE, it wasn't ment for turning-on/off the noise canceling feature, but having the phone away from your face MEANS the noise canceling WILL FAIL (both sound feeds picking up the same sound = must be noise) As I see it, IF YOU MIGHT WANT TO READ IT, YOU MIGHT WANT TO DO IT ON LOUD to your listener, right? which is not stopping to work when you put your phone away from your face (proximity sensor works fine). And I don't think they designed it like that, because they didn't conceive us using the phone away from our face without the "speaker" feature on.