[Q] Nexus 6 Video Recording Hiss topic

I noticed after recording a couple videos at 1080 and 4k that I'm getting a pretty noticeable hiss in the background. I tried changing roms, kernels, camera apps, nothing has worked in getting rid of the background hiss. Does anyone else experience this or know of a way to get rid of this, or should I take the phone back to T-Mobile? Sample below.

https://www.youtube.com/watch?v=FmjN...ature=youtu.be