Each year, about 3,300 people in the U.S. are diagnosed with an acoustic neuroma (vestibular schwannoma), a non-cancerous tumor that develops on the main nerve that connects the inner ear to the brain.1 Over time, this benign, slow-growing tumor can compress the nerve, resulting in hearing loss, tinnitus (ringing in the ear), dizziness, and more.
In this guide, we explain what an acoustic neuroma is, what causes it, symptoms to look out for, and how it is diagnosed and treated.
Table of Contents:
What is an Acoustic Neuroma? (Vestibular Schwannoma)
An acoustic neuroma (vestibular schwannoma) is a benign tumor that grows along the vestibulocochlear nerve. This nerve transmits sensory information required for both hearing and balance from the inner ear to the brain.
An acoustic neuroma tumor forms due to an overproduction of Schwann cells. The body naturally produces these cells to help insulate and protect delicate nerve fibers. However, an overproduction of Schwann cells can form a noncancerous (benign) tumor.
Over time, as the tumor grows, it can begin to affect hearing, balance, and even cause one-sided facial numbness, weakness, or paralysis. If the tumor becomes large enough, it will eventually become life-threatening.
What Are the Symptoms of Acoustic Neuroma?
The most common symptom of acoustic neuromas, occurring in roughly 90% of people, is gradual hearing loss in one ear (unilateral hearing loss) on the side the tumor is growing.2 Symptoms often develop slowly over multiple years, making them easy to miss at first.
Common symptoms of acoustic neuroma include:
- Sudden or gradual hearing loss typically only in one ear
- Ringing, buzzing, or hissing in the ear (tinnitus)
- A sensation of pressure or fullness in the ear
- Unsteadiness and balance issues
- Dizziness and nausea (vertigo)
- Facial numbness, weakness, or paralysis
- Headaches
- Difficulty swallowing
- Your voice sounding different to your own ears
If you or a loved one is experiencing any of the above symptoms, it’s important to seek professional medical care as soon as possible.
What Causes Acoustic Neuromas?
Acoustic neuromas develop from an overproduction of Schwann cells along the vestibulocochlear nerve. These Schwann cells normally form a protective covering around nerves, helping them send sensory signals between the inner ear and brain. However, when these cells multiply uncontrollably, it creates a noncancerous tumor along the outside of the nerves.
As the tumor grows, it can pinch the nerve fibers and interfere with or even block the electrical signals traveling between the inner ear and brain. This can lead to hearing loss, ringing in the ears (tinnitus), dizziness, and/or balance problems. If the tumor becomes large enough, it will eventually become life-threatening, interfering with other nearby brain structures such as the brainstem.
Below are some of the main factors that contribute to acoustic neuroma development:
Sporadic Gene Mutations (Unilateral Acoustic Neuromas)
About 95% of acoustic neuroma cases occur in only one ear (unilateral) and are caused by sporadic (sudden) genetic mutations.2 Sporadic gene mutations are nonhereditary, meaning they are not passed down from parents. These mutations and resulting tumor growth typically develop between the ages of 30 and 60.2
Genetic Disorders (Genetic Bilateral Acoustic Neuromas)
In rare cases, acoustic neuromas form in both ears (bilateral). Bilateral acoustic neuromas only occur in people who have a rare genetic disorder known as NF2-Related Schwannomatosis (NF2).3 This is an inherited mutation in chromosome 22, passed down from one or both parents, that affects the gene responsible for the production of Schwann cells.
The average age of onset is 18 to 24 years, with almost all NF2 patients developing bilateral vestibular schwannomas by the age of 30.4
Long-Term Loud Noise Exposure and Acoustic Neuroma Risk
Research shows that being around loud noise for many years may be linked to a higher chance of developing an acoustic neuroma.5 While the exact mechanism is unknown, researchers believe that long-term noise exposure puts the auditory system under stress, triggering uncontrolled cell division in Schwann cells.
How is Acoustic Neuroma Diagnosed?
An acoustic neuroma is primarily diagnosed using a professional hearing test (audiogrametric evaluation) to check for the presence of hearing loss, followed by an MRI scan to confirm the presence of the tumor.
Diagnosing an acoustic neuroma often takes time because the tumors grow slowly over multiple years before symptoms become noticeable. This makes attending routine hearing exams especially important.
Comprehensive hearing tests help identify patterns of hearing loss early. If hearing test results indicate the possible presence of a condition such as an acoustic neuroma, your hearing specialist can recommend appropriate follow-up testing and help connect you with the right specialists.
With early detection and appropriate follow-up, you can explore appropriate treatment options in a timely manner.
How is an Acoustic Neuroma Treated?
Treatment for an acoustic neuroma depends on several factors, including the size of the tumor, how quickly it is growing, the symptoms it is causing, and the person’s overall health.
Depending on these factors, treatment for an acoustic neuroma may involve:
- Observation: Small acoustic neuroma tumors that are not causing significant symptoms may be monitored with regular MRI scans and hearing tests. This allows doctors to track the tumor over time and determine whether more invasive treatment is necessary.
- Radiation Therapy: Stereotactic radiosurgery (radiation) uses highly targeted radiation to target the acoustic neuroma tumor and stop or slow its growth rather than surgically removing it.
- Surgical Removal: Acoustic neuroma tumors that are large, fast-growing, or cause severe symptoms like neurological changes may require surgical removal.
Even after an acoustic neuroma is successfully treated or removed, some symptoms may continue. If the tumor causes permanent nerve damage, hearing loss, tinnitus, balance problems, and/or other symptoms may not fully resolve.
However, ongoing hearing evaluations and follow-up care can help identify ways to manage them. For people who experience permanent hearing loss after acoustic neuroma treatment, hearing aids can help improve communication and quality of life.
With the right hearing solutions and ongoing care, many people are able to continue enjoying the activities and connections that matter most to them.
Schedule a Hearing Evaluation at an Audibel Clinic Near You
Acoustic neuromas are uncommon and often develop slowly, but changes in your hearing are always worth paying attention to. A comprehensive hearing evaluation can give you greater insight into your hearing health and peace of mind about what comes next.
If you have noticed symptoms of hearing loss, ringing in one ear, or other changes in your hearing, Audibel is here to help. Our hearing care specialists will take the time to understand your concerns, evaluate your hearing, and help you understand your options. Schedule a hearing evaluation at your nearest Audibel clinic today.
References:
- Kshettry, V. R., Hsieh, J. K., Ostrom, Q. T., Kruchko, C., & Barnholtz-Sloan, J. S. (2015). Incidence of vestibular schwannomas in the United States. Journal of Neuro-Oncology, 124(2), 223–228. https://doi.org/10.1007/s11060-015-1827-9
- Acoustic neuroma (Vestibular schwannoma). (2026, April 27). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/brain-tumor/vestibular-schwannoma
- Neurofibromatosis Type 2 (NF2). (2026, May 18). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/neurofibromatosis/neurofibromatosis-type-2
- Evans, D. G. (1998, October 14). NF2-related schwannomatosis (Updated 2023, April 20). In M. P. Adam, S. Bick, G. M. Mirzaa, R. A. Pagon, S. E. Wallace, & L. J. H. Bean (Eds.), GeneReviews. University of Washington, Seattle. https://www.ncbi.nlm.nih.gov/books/NBK1201/
- Cao, Z., Zhao, F., & Mulugeta, H. (2019). Noise exposure as a risk factor for acoustic neuroma: A systematic review and meta-analysis. International Journal of Audiology, 58(9), 525–532. https://www.researchgate.net/publication/332599758_Noise_exposure_as_a_risk_factor_for_acoustic_neuroma_a_systematic_review_and_meta-analysis
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