A month and a half. I am experiencing the opposite so far. The big problem for me is the refrigerant gas sound that starts few minutes after the compressor starts.
I've recently bought a Series X and I am very frustrated. I have it in the living room and it is very LOUD. (higher than the TV when the compressor starts).
I made two videos to show it:
Video 1 - Only the Noise:
Video 2 - TV On as a reference: