Such "hidden" hearing loss, not evident in the audiogram (a test that measures hearing sensitivity), is also apparent in human listeners who experience persistent tinnitus, but otherwise normal sensitivity.

BBC: Viewpoint: Does deafness contribute to dementia?

Several weeks later, although hearing sensitivity had recovered to normal levels, activity in the auditory nerve connecting the inner ear to the brain remained impaired.

BBC: Viewpoint: Does deafness contribute to dementia?

Sensitivity training is now accepted as a normal part of workplace indoctrination.

FORBES: Magazine Article