One of the many issues the Pixel 2 and Pixel 2 XL have been revealed to have is poor audio while recording video. While we're not sure if this affects all units, it definitely affected Artem's, and I've noticed the problem in some videos I've shot as well on my Pixel 2 XL. Google has confirmed that the problem has been resolved in the second 8.1 Oreo developer preview, and we've got video samples from before and after to prove it.
The best way to demonstrate the fix is just for you guys to hear the difference. Here's a sample of a recording taken on a Pixel 2 XL running Android 8.0 Oreo, taken by an owner named Jose Nieves:
And here's a sample of the same clip taken on a Pixel 2 XL running Android 8.1 Oreo DP2:
The difference is as clear as night and day. Whereas the audio previously sounded muffled, almost like the phone was underwater, it's perfectly clear in the second video. This is also corroborated by a reddit user, /u/ThisIsTechToday, who decided to make a full comparison regarding the changes in 8.1 DP2. Even further evidence can be found in this collection of videos shot by an owner named Eugene Monnier in his car of the same song playing.
I'm sure this amount of evidence is sufficient, especially since many of you had been experiencing the same issue since launch. We don't know when this fix will hit the stable channel, but given how widespread this issue is, hopefully it's sooner than later.