Audio is static when video is recorded in apps?

On my iPhone 6, there is a new problem that I just noticed this week that whenever I record a video in apps downloaded from the app store such as snapchat and instagram, there is a loud static sound and none of the actual audio or voices are heard. It can't be a microphone issue, because the microphone on my phone works fine when i try to record a video using the camera app. I've tried deleting and redownloading the apps, and restarting my phone, but the problem won't go away.