Broken Secrets

Headphones Can Be Used As Microphones

December 7, 2009 at 1:28 am Chad Upton 4 comments

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:

BrokenSecrets.com

Photo Credit: steveyb (Creative Commons)

Entry filed under: Be Frugal, Hacks. Tags: broken, hack, headphone, mic, microphone, secret.