How To Use Your Headphones as a Microphone

Quick tip today for those situations when you find yourself without a microphone. Say you come up with a cool idea and need to get it down quickly. You just want to beatbox or sing it into your computer but you've got nothing to record your voice with... or so you thought. Chances are you've actually got something hanging around that will do the trick in a pinch...

That's right your headphones! A speaker is designed to take electrical audio signal and run it through a coil in a magnetic field. Changes in the magnetic field produce movement in the speaker cone which turns out to be the vibrations you hear as sound. A microphone works in the opposite way; Movements of the diaphragm cause fluctuations in the magnetic field, forming electrical currents in the coil, which are then amplified and recorded as audio. Essentially they are the same things, just flowing in opposite directions and optimized for different tasks.

What this means is, you can take your headphones and plug them into a mic port on your computer for recording! Just speak into one of the cups at a decent volume and you should be getting signal. Don't go expecting boutique tone here though, you won't really be using it for finished productions and they won't be as sensitive as a proper mic, but if you just need to sketch down an idea so you don't lose it this is perfect. Your results will vary with the headphones you choose and generally speaking, the larger the speakers in them, the better. You probably won't be able to get much sound out of iPod buds for instance, without screaming into them.

The only downside here is, unless you have a second pair of headphones, you won't be able to listen at the same time. If you're trying to record in time with audio playing, you can probably get away with using speakers since the headphones aren't going to pick up that much background noise. Another quirky bonus is that with two ear cups, you get two mics. If you're going for some crazy sound design you could record something in stereo with the headphones placed on either side of it. When playing back it should sound like the recording is inside your head! Try flipping the phase of one channel for a different sound.

So the next time you have an idea you need to get down quickly, give it a try. Once you've got that rough sketch recorded, it's a lot easier to reproduce it in your audio workstation without having to worry about forgetting it.