How to temporarily redirect sound through speakers whilst headphones are plugged in?

I'm creating .wav files by playing the audio through speakers and catching it in the mic on my headset. I was wondering if there's a way to toggle the sound between the speakers and the headset without constantly plugging in and unplugging the headset, so that I can record something with the headset and then immediately check how it sounds through speakers. There should be a way to do this as it's extremely simple (on / off / on / off) -- I'm just not sure where to look.

 

It's easier to buy a cheap mic.

Anyway, if sound comes out the computer speakers, then goes back through the mic, it may cause feedback. Depends on how the mic is setup.