You have to look closely at the actual test protocol, which they rarely share. And in reality noise is hard to measure and hard to understand. There is also SPL and SWL, which are not the same. The marketing department has no clue and convert back and forth with approximations, adding or losing decibels, and nobody ever checks or really knows or, usually, cares. We need third party reviewers with actual sound meters or the numbers mfrs give us are practically useless. This is why I am prioritizing selling beta units to people who can actually test the units.