How did my hearing decline? Hearing loss can happen for many reasons, including deteriorative changes that occur naturally due to aging. Wear and tear on the eardrum, middle ear bones and muscles or inner ear hair cells and nerve function are common changes to the auditory system that result in hearing loss. Hereditary factors, noise exposure, side effects of medications and other medical conditions may contribute to hearing ability. Hearing loss can happen very gradually over years starting at age 40 or earlier, with the addition of precipitating factors, or suddenly. A sudden hearing loss must be evaluated by a physician immediately. Otherwise, hearing evaluations should be a part of overall health maintenance.