I have this laptop (Acer Aspire E 14) with only one audio port, my earphones also only has one plug, when I connect it to my laptop I will be given an option for which of the functions I want to use (Line In, Mic in, Headphone, Speaker Out, and Headset), but I can only use one of them, I wanted to use both headphone and mic functions, I have been looking around the internet and I still can't find any solutions to this, I want to know how to use the functions at the same time, if I need an app for it, please provide links to download, 
