https://wccftech.com/airpods-pro-firmware-2c54-has-bad-noise-cancellation-better-bass-response-apple-has-pulled-the-update/

Apple released firmware 2C54 for the AirPods Pro in mid-December and it comes with a gift for users in the form of bad noise cancelling.

Since its launch, Apple has released two firmware updates for the AirPods Pro so far. 2B588 was released back in November of 2019 and 2C54 released only recently in mid-December. It appears as though the latest update might not be playing along nicely with a lot of users out there as some believe that noise cancelling may have taken a hit. This is particularly noticeable when you turn on noise cancelling in an environment that has a lot of low-end noise, such as the engine of a plane or a train. The noise isolation in the bass range is not that good with the 2C54 update. In fact, RTINGS did a test of their own and found out the following: