[Q] Can't use microphone when headphones are plugged in topic

If I'm walking somewhere and am listening to music, I have my headphones plugged into the phone. If someone calls me during that time, I have to unplug the headphones and use the built-in speaker like normal. I tested once with a friend and he could hear me slightly if I yelled very loudly (with headphones plugged in), but for normal use I have to unplug the headphones entirely.

Is there any way to use the microphone for a call while I have headphones plugged in?