[Samsung Galaxy S7 Questions and Answers] clonk:
This post pertains to the issue addressed in the following thread:

https://xdaforums.com/galaxy-s7/help/dont-s7-s7-edge-users-post-recorded-t3535820

I posted the following to the Samsung support community last week...

Description & Solution

The intent of this post is to offer an easy solution to S7 and S7 Edge owners experiencing the recorded audio crackling issue. I have two devices that were suffering from the problem: an S7 and an S7 Edge. I purchased both devices brand-new. The crackling bursts plagued my recorded video footage as well as my voice recordings on both devices. My S7's crackling issue was bad enough. But on my S7 Edge, the crackling was simply horrible - far worse than my S7 had ever been. I have seemingly discovered a way to eliminate the crackling sounds on both devices.

I came up with this simple procedure myself after many phone calls to Samsung customer support --who would always claim they have never heard the complaint before-- and a great deal of web searching. Like my calls to Samsung, my web searches rendered no viable solutions, nor even a single factually convincing explanation as to the cause of the crackles. There were only mere guesses as to why the crackling perpetually manifests from the audio input circuitry (microphone stage) on certain S7s, S7 Edges and older S model Galaxy devices (dating as far back as the S4). It has been frustrating. And Samsung's repeated insistence that they have never heard the complaint before each of my calls, then reading that other folks were told the very same thing, made my situation all the more disturbing.

So, without further ado, below is my fix. Or at least it has seemed to fix both of my S7 devices - your mileage may vary. And this solution is so simple that it almost makes me want to slap myself for not thinking of it sooner.

Make sure your battery is fully charged and launch your camera app. Tap the 'record' button and set your phone on a table, allowing it to record for at least 1 hour. The crackles appear to be electrostatic charges existing within the audio input circuitry of certain S7s and other older Samsung phones. By allowing your device's audio recording function to "burn in" (as it were) for one hour or more, you should be able to permanently deplete those electrostatic charges, thus eliminating the periodic discharges during your recording sessions and therefore the crackles that superimpose on your video and audio files. You may be able to perform this same burn-in function with an extended audio recording. But since I haven't tried that yet, I don't know whether it would render the same result after just one hour of record time, or whether it may require a longer period.

So that's it. I now have two S7 devices that are finally free from emitting those annoying crackles on my recordings. I can leave either device on over night and make a new video in the morning and it's consistently clean! Please try this method and let me know if it works for you as well.

And I posted the following update to the Samsung support community this morning...

Update:

Since my last post, I've performed this procedure on yet another S7. The result is that now the problem appears to be completely gone on it as well. And I think I've proven something else. I did not perform this latest audio recording burn-in session with the third S7's pre-installed camera app video recorder feature, as was done with my own two S7s. Instead, I used the 'Audio Recorder' app from Sony Mobile Communications in stereo mode to record a 1-hour audio file on the device. But you know what? As with my two S7s, this burn-in seems to have totally eliminated all of the crackles/pops from the device as well. So now it seems clear that you don't have to have a huge amount of free storage available to perform the fix, because you can simply use a long audio recording session.

So the fix is: Simply use a 1-hour audio recording session to bleed down all of the electrostatic that for some reason seems to build up on some devices during the manufacturing process. I'm becoming more and more convinced that this is the solution, everyone. No longer a single crackle on any of three S7s that were previously suffering from the issue! Hopefully S7 owners suffering from the recorded audio crackling problem will find my posts herein and thus be able to easily fix their devices.

At this point, I believe that the solution described herein may genuinely and completely resolve the intermittent, but perpetual, recorded pops and crackles issue experienced on S7 /S7 Edge video and audio recordings by some device owners.

Cheers