Sorry, for my english! When starting, the car initially holds about 1000rpm. and is peace and quiet. I downloaded a program for decibels / It is clear that it is not the most accurate, but ... / and at these speeds the situation is as follows 68, but when the engine warms up, falling to about 750 rpm. and inside it becomes as if I am in a vacuum, it reaches over 80 db

Any ideas to get rid of this noise?

Superb 2021 2.0 tdi