An acoustic neuroma is a rare, benign tumor that occurs on a nerve that connects the brain to the inner ear. It is usually a very slow-growing tumor. Although an acoustic neuroma is noncancerous and will not spread throughout the body, they can grow to become quite large. When this happens, it can damage parts of the brain. This is due to the fact that the branches in the nerve that runs from the brain to the inner ear are directly associated with your hearing and balance. If the acoustic neuroma becomes big enough, it can place significant pressure on the nerve which may result in hearing loss. It is estimated that about ten out of every one million people are diagnosed with an acoustic neuroma each year.