Some time ago, my iPod's microphone stopped recording sounds at their full volume. I typically use the microphone only occasionally for videos (which I might not have played back soon) or Voice Memos, so it could have been months before I noticed this problem existed.
An Internet search for this problem led me to a couple of YouTube videos, which led me to clean out the microphone gently with a needle, which restored the microphone to its apparent former sensititivity.
Doing the analogous cleaning for my iPad 2, whose microphone doesn't record any noise at all now, didn't help. Although there was a time when I got back some recording sensitivity by blowing hard into the microphone hole, that microphone seems to be totally unresponsive now.
