I have just got my iPhone and this is the second week I am using it.

But there is one thing that I really wonder if it is ok. When ever I turn my phone to speaker mode while talking, my voice seems to be very soft and laggy to the other party on the phone. All of my friends complain that they couldn't hear me.

When I move the mic close to my lips, my voice turned muffled instead.

It is ok when I talk through the normal mode. The earplug is slightly better than the speaker mode, but not as loud as when in normal mode. Some of my friends still complain they cannot hear me when I am using the earplug.

Is there anyway to fix this?

anyone has this problem before?