We all risk exposure to harmful noises which could have an effect on the sensitive structure of the inner ear. I use the Decibel X app to measure the intensity of sound but then how accurate can the free apps be?
I think that we often get exposed to dangerous noise levels, without even realizing it. I would easily go for the NIOSH Sound Level Meter app that meets certain testing criteria. It is equally important to settle on accurate app.
The apps have been tested by researchers and the results showed that the apps built for the Android platform weren't as reliable as those built for the iOS platform. The tests also showed that the age of the phone affected the outcome as well. Newer models do a better job of measuring noise levels. These tests were conducted around 2014-2015. There might be something more current that I'm not aware of. I learned about it at work. I'll try to see if I can locate the info or at least a link to the study.
As quickly as technology changes, it's possible that both Android and iOS both measure sound equally well now. I guess their testing methods could have been disproved by now too, but at least at that time, that particular study found these apps were pretty reliable.