I'm having this problem and there's absolutely no debris in my iPhone 6's audio port. I checked and checked again, I used Q-tips meant for electronic devices and a paper clip in it but nothing came out. I checked the audio port under an industrial strength light and it's completely clean up there.
Anyway, for me, this static headphone jack issue started just a few days ago. I was watching a video when Voice Control kept popping up whenever I heard static in my earphones. I have a pair of cheap but super reliable JLab earphones with a built-in mic that have never given me problems before. These earphones work 100% with every smartphone/tablet/mp3 player/computer in my house except for my iPhone 6. The earphones' headphone jack has a metal base, so maybe that's the culprit. I still don't know how to cover it properly.
Sometimes the problem goes away, but it always comes back with a vengeance. I'm so sick of this. There's no reason why my earphones shouldn't work properly with my iPhone 6. Other earphones, like the Apple Earpods or earphones/headphones without a built-in mic work properly with my iPhone, but not the JLabs, which are waaaay more comfortable than the rest. I swear, Apple is colluding against other headphone makers to ensure their proprietary earphones' success.
People without the issue, how did you solve it? Did you revert to using the official Apple earphones or earphones without that metal ring at the base?