the camera/microphone will not pick up any sound

i've only had my ipod for a week or so and i have looked after it very well, but a few days ago i tried recoring a video and it all worked fine until i played it back because i found that the only sound there was, was like someone had put there thumb over the microphone, there was some sound of the actual goings on but it was ver very quite. if you could help me with this issue i would be very thankfull.

thanks

Message was edited by: lukegee9696