Sleep A20 decibel levels

Just received the Sleep A20s and am trying them out. They’re very comfortable and seem to be great for sleeping and tinnitus.

However, something is very weird with the db levels. My iPhone says the db level is 60 and it’s definitely not 60. And when I lower the volume to around 30 and one click more and it’s 0 (zero). Nothing in between.

I compared the volume to AirPods and seems like 60 on these is equivalent to 40 something on the AirPods.

Might not be an issue for some, but I want my health app to get proper data for my db levels because of potential hearing loss.