Hearing loss is most commonly caused by excessive noise exposure or through the natural aging process.  The hearing loss may be due to middle ear problems, such as glue ear, otosclerosis (excess bone growth behind the ear drum), chronic ear infections, or a cholesteatoma (cyst behind the eardrum).  Causes of inner ear hearing (damage to the sensory hair cells) include noise exposure and the aging process, medications toxic to the inner ear, Meniere’s disease (excess fluid production in the inner ear), virus infections and genetic causes. See: Common Causes of Hearing Loss