Headphones Can Be Used As Microphones
You forgot your microphone at home and you’ve got an online meeting in five minutes. This secret might save you.
While it might be hard to come by a spare microphone, the ubiquity of mp3 players makes it easy to find a pair of headphones. If you plug headphones into the microphone input on your computer (or other electronics), you can speak into the LEFT headphone as if it were a microphone.
This might sound crazy, but this is possible because microphones and speakers (or headphones) are very similar. A microphone converts sound waves to electrical impulses while a speaker converts electrical impulses to sound waves. Although they do the exact opposite function, they actually use the same principle and components to do so.
In a microphone, the sound waves hit the diaphragm, causing it to vibrate at a specific frequency. A magnetic coil attached to the diaphragm moves with the vibrations which induces an electric current in the wires. This current is often converted to a digital signal to be recorded or sent across the internet.
A speaker works the exact opposite way. An electric current on a wire causes a coil to move; a diaphragm attached to the coil pushes air at a specific frequency which generates sound waves for your ear to pick up.
I discovered this secret a long time ago, when I lost the microphone for my Rap-Master Keyboard. I found a demo video you can check out:
Photo Credit: steveyb (Creative Commons)