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An acoustic neuroma often goes unnoticed for a long time because its initial signs may seem insignificant. A difference between the two ears, unilateral tinnitus, or a certain sense of instability can become part of one’s daily life without immediately raising any alarm.
Furthermore, when one ear retains good hearing, it can partially compensate for the ear that is losing its ability. As a result, some people may not clearly perceive how much their hearing has changed until the difference between the two sides has become significant.
An acoustic neuroma, also known as a vestibular schwannoma, is a generally slow-growing, benign tumor that develops on the nerve associated with hearing and balance. Its most characteristic manifestations include unilateral hearing loss, tinnitus in one ear, and certain balance problems.
At Clinicaudio, when a person explains that one ear “does not respond the same way” as the other, that asymmetry is one of the first things we analyze. An audiometry test allows for an objective comparison of both ears, making it possible to detect differences that may have gone unnoticed for months.
La audiometría no diagnostica un neurinoma, pero sí puede indicar cuándo una pérdida auditiva asimétrica necesita estudiarse con mayor profundidad.
¿Notas que un oído responde claramente peor que el otro?
What is an acoustic neuroma?
An acoustic neuroma, or vestibular schwannoma, is a benign tumor that develops from the Schwann cells of the vestibulocochlear nerve—the nerve that transmits information related to hearing and balance between the inner ear and the brain.
Although traditionally known as an “acoustic” neuroma, the term vestibular schwannoma is anatomically more accurate because it typically originates in the vestibular portion of the nerve.
This tumor typically grows slowly. As a result, its symptoms may develop over the course of years before truly becoming noticeable. As it increases in size, it can affect the nerve responsible for hearing and balance; in the case of larger tumors, it may also exert pressure on nearby structures, such as the facial nerve or the trigeminal nerve.
The fact that it is benign means it is not cancer and does not metastasize; however, its location requires that it be monitored and treated appropriately.
Causes of acoustic neuroma: why it develops
In most people, it occurs sporadically, with no specific cause that can be identified.
No existe una forma conocida de prevenir la mayoría de estos tumores y no debería asumirse que hábitos cotidianos como utilizar auriculares o haber estado expuesto a ruido sean su causa.
There is, however, a specific genetic condition associated with the development of vestibular schwannomas on both sides: NF2-related schwannomatosis, formerly known as neurofibromatosis type 2. It is a rare hereditary disease that requires specialized medical follow-up.
In typical cases, the neurinoma appears on only one side.
Symptoms of acoustic neuroma
Symptoms typically appear gradually and can be confused with other hearing-related conditions.
Unilateral or asymmetric hearing loss
It is one of the most characteristic symptoms.
A person may notice that their hearing is worse in one ear, but the change can be so gradual that the other ear ends up compensating for it.
This explains very common situations:
- Always use the same ear when talking on the phone.
- Turn your head to hear better.
- Experiencing greater difficulty when someone speaks from a specific side.
- Losing clarity in noisy environments.
- Feeling that one ear is “not responding” the same way as the other.
At Clinicaudio, we place special importance on this comparison. When someone seeks a consultation due to a difference between their two ears, evaluating them separately makes it possible to quantify the asymmetry—even if the individual still appears to function well in their daily life.
If you would like to learn about other causes and signs of this issue, you can consult our guide on single-sided hearing loss. Because the ear with better hearing compensates for the other, it can take a long time for unilateral hearing loss to be detected.
Tinnitus in one ear
Another common symptom is unilateral tinnitus: a ringing, buzzing, or other noise that occurs in only one ear.
Having unilateral tinnitus does not mean that a neuroma is present. Tinnitus can have many different causes.
However, a question that our professionals at Clinicaudio frequently ask is whether the tinnitus occurs in one ear or both. When it is persistent and unilateral—especially if there is also a difference in hearing between the two sides—it warrants further investigation.
You can find more information in our guide on tinnitus: causes, symptoms, and treatment.
Instability or balance problems
The vestibular nerve plays a role in balance. When it is affected, problems with maintaining stability may arise, such as a sensation of walking on an unstable surface or, in some cases, vertigo.
Not everyone experiences these symptoms, and severe vertigo is not necessarily the primary manifestation of the neuroma.
Además, existen muchas otras causas de inestabilidad.
In our guide on dizziness or vertigo—and when the cause might lie in the ear—we explain how to distinguish between these symptoms and what information helps determine their origin.
Otros síntomas menos frecuentes
When the tumor grows larger and begins to affect nearby structures, the following may occur:
- Entumecimiento facial.
- Tingling on one side of the face.
- Facial weakness.
- Major balance problems.
- Headache or other neurological symptoms in advanced cases.
Very large tumors can end up compressing nearby brain structures, although it is now less common for them to reach that stage before being diagnosed.
Is it dangerous? Is it a malignant tumor?
An acoustic neuroma is benign.
It is not cancer and does not spread to other organs.
The problem lies in where it grows. The space around the internal auditory canal and the brainstem is limited, so a tumor that increases significantly in size can compress important nerves and structures.
In advanced cases, it can lead to significant hearing loss, facial nerve disturbances, and—rarely—neurological complications such as hydrocephalus.
This does not mean that all diagnosed individuals require surgery.
In fact, some small neurinomas grow very slowly or remain stable for years, so one possible strategy is simply to carry out periodic check-ups.
How an acoustic neuroma is diagnosed
The process often begins long before the tumor is visible.
It starts with noticing that the two ears are not functioning the same way.
Audiometry: detecting asymmetry
Audiometry evaluates each ear separately and makes it possible to determine hearing thresholds at different frequencies.
A significant difference between the two sides may indicate the presence of asymmetric hearing loss that requires investigation.
An assessment of verbal comprehension can also be conducted to determine how each ear processes speech.
Audiometry alone cannot confirm a neuroma, but it is often one of the first steps when unilateral hearing loss or tinnitus is present. If a pattern emerges that requires further investigation, an MRI may be indicated.
At Clinicaudio, when a person seeks a consultation due to poorer hearing in one ear, the comparison between the two sides is one of the most important pieces of information in the assessment.
You can learn more about this test in our article on what an audiometry is and how it is performed.
Other hearing tests
Depending on the case, additional tests may be used to examine how auditory information travels from the ear to the nervous system.
Brainstem auditory evoked potentials, for example, can provide information about the transmission of the auditory signal.
However, when there is a significant clinical suspicion, these tests do not replace imaging.
Magnetic resonance imaging: the gold standard test
Magnetic resonance imaging, typically with contrast, is the gold standard for visualizing and either confirming or ruling out a vestibular schwannoma.
Allows one to learn:
- If a tumor actually exists.
- Its size.
- Its location.
- Its relationship with the nerves and adjacent structures.
An MRI scan can detect even very small tumors that would not be visible through other types of examinations.
At this stage, it is important to distinguish between functions: Clinicaudio can detect and characterize hearing impairment, whereas the medical diagnosis of a neuroma and the recommendation for imaging tests fall under the purview of the otolaryngologist and the relevant medical team.
Do you notice a clear difference between your two ears? Detecting this is the first step toward determining whether it requires further investigation.
Treatment of acoustic neuroma
There is no single way to treat all neurinomas.
The decision depends on factors such as:
- The size of the tumor.
- Yes, it is growing.
- The hearing that a person retains.
- Age.
- General state of health.
- The symptoms.
- The location of the tumor.
The three main strategies are observation, radiosurgery, and surgery.
Active observation
When the tumor is small, grows slowly, or causes few symptoms, the specialist may recommend periodic check-ups rather than immediate intervention.
Follow-up is typically carried out through magnetic resonance imaging and hearing tests.
The goal is to determine whether the tumor remains stable or is growing before making further decisions.
Stereotactic radiosurgery
Stereotactic radiosurgery uses radiation directed with high precision toward the tumor.
Systems such as Gamma Knife are examples of this technique.
Its primary objective is not to remove the neurinoma, but rather to halt its growth while attempting to preserve, as much as possible, the function of nearby structures.
It may be an option for certain small or medium-sized tumors, depending on the characteristics of each patient.
Surgery
Surgery may be recommended when the tumor is large, continues to grow, or is causing significant symptoms.
There are various surgical approaches, and the choice depends on factors such as size, location, and residual hearing.
One of the primary objectives is to control the tumor while attempting to preserve the facial nerve and auditory function, whenever possible. In some cases, complete removal is not attempted if doing so would pose an excessive risk to nearby neurological structures.
How a neuroma can affect hearing
Hearing loss associated with a neuroma can progress in different ways.
Treating the tumor also does not necessarily guarantee the recovery of hearing that has already been lost. One of the goals of early diagnosis is to provide more options for attempting to preserve existing function.
Following diagnosis and treatment, it may be necessary to evaluate specific hearing solutions.
Depending on the residual hearing, the following options may be considered:
- Conventional hearing aids.
- Systems designed for one-sided losses.
- Bone-conduction systems.
- Cochlear implant in certain selected cases.
- Other specialized solutions, depending on the condition of the auditory nerve.
The recommendation should always be made after determining how much hearing remains in each ear and how the individual perceives speech.
At Clinicaudio, this part of the follow-up process is especially important: it is not just about knowing how many decibels have been lost, but about understanding how that hearing deficit affects conversations, meetings, phone calls, and situations involving background noise.
When to consult a specialist
Not every instance of unilateral tinnitus or hearing loss in one ear is due to a neuroma.
In fact, there are much more frequent causes.
What should be avoided is normalizing a persistent difference between the two ears without knowing why it exists.
Request an assessment if:
- You notice that one ear hears noticeably worse.
- You always use the same ear when talking on the phone.
- You have persistent tinnitus on only one side.
- Instability occurs, along with changes in hearing.
- The difference between the two ears appears to increase progressively.
- You experience numbness or changes in facial sensation.
There is a different situation that requires more urgent action: sudden hearing loss. If you notice a significant drop in your hearing over the course of a few hours or days, you should not wait to see if it recovers on its own; it requires prompt medical evaluation.
At Clinicaudio consultations, we encounter individuals who initially describe their problem as “a blocked ear” or “an ear that doesn’t hear quite as well.” Comparing both sides makes it possible to determine whether an asymmetry truly exists and to decide whether further evaluation is necessary.
Frequently asked questions about acoustic neuroma
Is an acoustic neuroma cancer?
No. It is a benign tumor and does not metastasize.
However, it must be monitored because it can grow in an area close to nerves and important neurological structures.
Are acoustic neuroma and vestibular schwannoma the same thing?
Yes.
Vestibular schwannoma is the more anatomically precise term, while acoustic neuroma remains a widely used designation.
How do I know if my hearing loss could be due to a neuroma?
It cannot be determined solely by the symptoms.
Hearing loss that is clearly worse in one ear—especially if accompanied by unilateral tinnitus—may warrant an evaluation.
Audiometry can detect asymmetry. If the results or symptoms warrant further investigation, the specialist may request an MRI to confirm or rule out a tumor.
Do all neurinomas require surgery?
No.
Depending on its size, growth, symptoms, and patient characteristics, the options may include observation, radiosurgery, or surgery.
Can hearing be restored?
It depends on each case.
Hearing lost prior to treatment is not always recovered, although certain treatments may aim to preserve existing hearing. When permanent hearing loss remains, various options for aural rehabilitation are available.
Is an acoustic neuroma hereditary?
Most are sporadic.
Bilateral vestibular schwannomas may be related to NF2-associated schwannomatosis, a rare genetic condition that requires specialized evaluation.
El primer paso es detectar la asimetría auditiva
Acoustic neuroma is rare, but its initial symptoms can resemble those of many other hearing-related issues.
For this reason, at Clinicaudio, we do not view unilateral hearing loss as a diagnosis in itself. The first step is to determine what is actually happening.
An audiometry test allows for a comparison between both ears, quantification of the difference, and an assessment of whether there are also changes in speech comprehension.
If we find an asymmetry that has no obvious explanation, the next step may be a referral to a specialist for further evaluation.
Most people with poorer hearing in one ear will not have a neuroma, but determining the cause of that difference remains important.
Do you notice that one ear hears worse than the other, or do you have tinnitus in only one ear?
Related articles
Is your hearing worse in one ear?
The ear with better hearing can compensate for a long time, causing unilateral hearing loss to go unnoticed. Turning one’s head to listen, consistently using the same ear for phone calls, or experiencing greater difficulty when sound comes from a particular side are all subtle signs worth noting.
In our guide on single-sided hearing loss, we explain why this compensation occurs and when it is advisable to undergo an evaluation.
Do you have a buzzing sound in only one ear?
Unilateral tinnitus can have various causes and, on its own, does not necessarily indicate the presence of a neuroma. However, if it persists or occurs alongside a difference in hearing between the two ears, it warrants further investigation.
In our article on tinnitus, we explain why this ringing sensation can occur, how it is evaluated, and what options exist to reduce its impact.
