"When we get the proper correction in the ear for the hearing loss, we're exercising portions of the brain to keep it from getting weak," Dennis Thomas said. "If we don't do anything with untreated hearing loss, the cognitive decline tends to excel."

"It's not really about getting a hearing aid, it's finding out what the problem is," said Thomas. "Sometimes it's just earwax that needs to be removed. Sometimes it's more medical intervention."

Many have developed dementia or Alzheimer's and have never treated their hearing problems.

Hearing specialists recommend anyone who starts to notice issues with their hearing go in for a simple hearing exam. The specialist will use a video otoscope to look into the ear, then try to find any wax buildup or see if the eardrum is damaged.

"A lot of times, there's more damage that sets in by not taking care of the problem," said Thomas.

Beltone Central California offers free hearing exams to patients to help with early diagnosis, in hopes of finding a solution and preventing any cognitive decline.