What is it?
Hidden hearing loss (HHL) is characterized by an audiogram that reflects normal hearing sensitivity across all frequency ranges but speech-in-noise tests reveal a deficit. In the case of HHL, the stereocilia are healthy but auditory nerve fibers are damaged, resulting in a compromised connection between the ears and the brain. Patients will report difficulty understanding others.
What causes it?
Damage to the nerve fibers, usually from noise exposure, often combined with aging. HHL is caused by a problem in the peripheral auditory system, whereas an auditory processing disorder is due to a deficit in the central auditory system.