What Causes Hearing Loss after Viral Infection?
So what is the link between viral infections and hearing loss? For the most part, the evidence which links sudden hearing loss and viral infection is largely circumstantial.
While between 17% and 33% of people with sudden hearing loss report experiencing a recent viral infection, it is also important to note that in one study, 25% of patients visiting one otolaryngology clinic had experienced viral infection without hearing loss in the month prior to their visit (eMedicine).
However, ear examination of people who experience hearing loss after viral infection show ear damage in the cochlea which is consistent with injuries that occur as a result of viral infection. Structural changes which result in hearing loss (such as neuronal loss and atrophy of certain ear structures) have been noted in people who recently experienced mumps, rubella, measles, or herpes infections, among others.
The exact cause of hearing loss after viral infection is unknown, but studies show that during infections that affect the ears, the blood supply to the ears may be reduced, resulting in oxygen depletion and ear damage.