An audio issue which had been plaguing the Google Pixel and Pixel XL has been fixed with the latest (February) security patch update which began rolling out yesterday, according to the latest user reports coming through. Users who have updated their Pixel or Pixel XL are now reporting that since updating the issue with the audio has been remedied and is no longer present. However, Google has yet to publicly announce that the update includes a specific fix for the audio issue.
This is an issue which has proved very problematic for Pixel and Pixel XL owners and there had been a debate going on as to whether the issue was the result of a hardware problem or a software issue. Although, if the latest user reports are correct then it would seem the latter was likely to have been the case. In terms of the issue, the problem was only noticeable when the volume on a Pixel or Pixel XL device was increased to one of the highest levels. At which point the sound reportedly became distorted.
Interestingly, on Reddit (where the fix was first reported), some owners are debating as to whether the update applies a true fix to the issue or whether the update has simply lowered the maximum volume setting slightly to offset the possibility of hitting a level which could cause the distortion to be heard. Although, the same commentators debating this point do note that if the volume has been limited in any way, it is not a noticeable limitation - which presumably is what matters the most. Without any firm confirmation from Google on the matter though, it is likely to remain unknown whether the actual issue has been fixed or whether the volume was lowered to offset the effects. In either case, if you are on the developer preview which was released last week, then it seems the fix is not included in that version. You will need to be running the very latest February 6 dated security update or the next developer version which will likely include the February fixes when it is released.