Are/how are you using background sounds feature on iPhone or other smartphone?

I just starting playing with this feature as I live by myself and wondering whether having background sound e.g. stream, ocean, pink noise, etc. might have beneficial effects for auditory and brain stimulation? Any research? Anecdotal information?

While I expect like others speech recognition is highest priority, I expect that there might be some benefits to auditory stimulation if one lives in a fairly quiet (in my case rural) environment. I do listen to music and audio books and talk on the phone etc. I did find interesting article that did not site references on the impact of concentration ability for studying (memorizing) with white noise and while beneficial to those that are extroverts it was detrimental to introverts. I do not have tinnitus but understand that background sound and other masking can be helpful. Anyway, exploring my sound landscape and options is interesting.

Since one can add custom background sound audio files, are there any that you have experimented with?