Make a version available for headphones with removable wires.
There are some headphones that have female 3.5mm jacks in the cups that allow the end user to replace their wires, such as the Monster® Inspirations.
This provides an easy way you add in a microphone, while keeping both in the same wire, and it also allows for an easy way to us this as a headset with mobile device.
Image was made for reference: http://bit.ly/1xjcHIM
This one is in the queue and we’re hoping to have it out within a reasonable time (2015). Love the pic.