https://www.theverge.com/2019/1/8/18174320/googles-pixel-3-update-audio-quality-video-recordings

Google is rolling out its first monthly update in 2019 for its flagship Android devices. The only listed change is a bug fix addressing an audio quality issue on both models of the Pixel 3 that occurs while recording video, as reported by users on Reddit.

Meanwhile, the Pixel 2 / 2 XL, Pixel / XL, and Pixel C are also receiving January updates to patch security vulnerabilities and generally just keep up shop. I received the update late last night on a Pixel 3XL unit that was having some stability issues, applied the update, and was greeted by a smoother experience, complete with the audio quality fixes.