Today, I was playing Bambo Flute where you blow into the microphone. It was working fine then but now it doesn't work. When I make calls they can't hear me and in Voice Memos dosen't work. In Video Recording it does. Any one help me please!
Connect it to iTunes and tell it to restore. Simple.
If it is a mic issue (hardware) then your only option is to get it repaired, or have Apple replace it. There are mall kiosks (around here anyway) that do repairs like this. I can't speak of their pricing model, but I imagine it's cheaper than the $150 Apple would charge you for an out of warranty replacement. If your phone is still covered by the warranty, Apple will replace it for free, so long as they don't detect any water damage.