From Norman Doidge's book "The Brain That Changes Itself", I learned that: Long term white noise exposure might be associated with hearing loss, especially age-related. The theory was that "nerves that fire together, wire together", too much white noise compared to clear sounds will cause the neural mapping for sounds to gradually become fuzzier, making distinctions between sounds will become harder.
"However, a recent study in the JAMA Journal of Otolaryngology–Head & Neck Surgery states that white noise’s lack of structure can worsen tinnitus symptoms. The study researchers also suggest that white noise could possibly “accelerate the ageing of the brain” and increase the risk for dementia" Study: https://jamanetwork.com/journals/jamaotolaryngology/article-...
Same is true of other kinds of background noise, such as computer fans, air conditioners or driving in a car. A while ago, based on some self study, I tried to 'fix' my tinnitus by targeting it with specific frequencies rather than noise, and that provided temporary relief by actually reducing the perception of the tinnitus briefly (like 5 minutes). But white noise has always increased it.