While I was looking around electronic stores I found this microphone that was less than a dollar or so but its basically a little cylinder with two wires.
How does this device work? When it receives sound does it alter the resistance and I can take a reading via a voltage divider?
Also, is the resistance dependant on the frequency it receives or the intensity or a bit of both? I don't really have more details but I can try to answer if theres some clarification. Also, if it works in a completely different way, tell me.