https://wccftech.com/google-is-rolling-out-adaptive-sound-feature-to-the-pixel-6-series/

Google has decided to quietly push out the Adaptive Sound feature to the Pixel 6 and Pixel 6 Pro. This feature is going to help the users adjust the phone's audio quality depending on the environment. Since last year, the Adaptive Sound feature has been an Android feature, some of the best Android phones have their version of this feature, too, and Google pushed this feature as part of a feature drop. Pixel 6 series did not launch with this feature, but Mishaal Rahman has discovered that this feature is now available on this phone.

Many, including Rahman, assumed that the feature was only released last year to fix Pixel 5's average speakers so it would not make its way to the Pixel 6 series, but that does not happen to be the case.