White noise improves learning by modulating activity in midbrain regions (2014)
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.