How Microphones Catch Your Voice

Have you ever sung into a microphone and heard your voice come out of a big speaker, loud and huge? A tiny whisper can fill a whole room! How does a little microphone do that? A microphone has a special job: it catches sound and turns it into a signal that machines can use. Let's find out how it works.

In this lesson you will: - Learn that sound is made of tiny wiggles in the air - Find out about the wiggly part inside a microphone - See how a microphone turns your voice into a signal - Try making your own pretend microphone

When you talk or sing, the air in front of your mouth wiggles back and forth very fast. These wiggles are called sound waves. You cannot see them, but you can feel them! Put your hand on your throat and hum a low sound. Do you feel it buzzing? That buzz is making the air wiggle, and that wiggle is your voice traveling out.

Inside a microphone is a thin, floppy part called a diaphragm (say it: DYE-uh-fram). It is a bit like a tiny drum skin. When the wiggles from your voice hit the diaphragm, it wiggles too - in and out, in and out. The louder you sing, the bigger it wiggles!

Here is the clever part. As the diaphragm wiggles, the microphone changes those wiggles into a tiny electric signal. A signal is like a secret message the wires can carry. That signal zooms down the wire to a speaker, which makes the air wiggle again - but much bigger. That is why your quiet voice comes out big and loud!