[Q] hard keys operation tester topic

hi guys, I've got a problem, and maybe you can help me solving it. I recently bought a pair koss portapro ktc as an upgrade from portapro classic. they have the 3 classic buttons for volume and play/pause control. the problem is that they're made for iOS, and the volume buttons aren't working at all. I tried with headphone button controller, but I can't configurate them, and I think the phone doesn't even recognize the pressure of one those buttons. there's an application that would allow me to test if the button's are even working? I mean, I want to know if the device (oneplus one) recognizes that I pressed button when I physically do this. I'm looking for an hard buttons tester, just that. if I'll be able find something like this I'll go through tasked and stuff's like that to set the buttons function properly. can somebody help me? (sorry for my English)