Screen difference

Dear,

Every iPhone has it's unique sound when you tap harder on the screen, it is because the hardware varies, capacity of battery, size of screen, weight of the mobile, height and width, and etc number of factors are there. So the noise will raise when you tap on the screen harder.

Dear, Only the sound may vary, it is not that the iPhone is hollow or empty inside the packing has some patterns to be followed, on following, it has a small linear space beneath screen, that carries the screen and display a level above other hardware.