Microphone Records Static

I have an iPhone 6 and I was trying to use an app which accesses the microphone and it only recorded static. I was trying to see if it was a problem with my phone and discovered that when using Voice Memos it only records static too. My camera records fine - both front and back camera. Sounds records with the camera. Siri works fine. There isn't any problems when making phone calls. Its just voice memo and a few apps. I've tried updating my software, restarting, etc. Any suggestions?