Disable mic in earbuds?

I Don't know what changed all of a sudden, but the last time I plugged my standard Apple earbuds into my iPhone, it started using the mic attached to the earbuds instead of the iPhone's internal mic, and the earbud mic is awful and barely even audible unless I practically put it inside my mouth. I tried pressing the button on the mic/volume thing but nothing happened. I tried turning the phone off and on and it's still defaulting to the earbuds mix