Microphones might seem like complicated pieces technology, but it doesn't take much to build one of your own. You can put together a simple microphone with the graphite stripped out of a number two pencil and tiny matchbox.
You'll need a few other things to finish the project, including a 9V battery, some basic wires, alligator clips and a speaker or pair of headphones -- but this build from YouTuber DaveHax is otherwise not too difficult. Just remove the graphite from your pencils extremely carefully, scrape a flat side on each piece, place them in the matchbox as demonstrated, and you're ready to wire it all up. It may not be as nice as a studio mic, but it works surprisingly well!
How to Make a Matchbox Microphone [DaveHax]