- Sudden sensorineural hearing loss (SSHL) is a rapid inner-ear hearing loss that can happen in one ear within hours or a few days.
- A same-day or next-day audiogram helps distinguish SSHL from wax, congestion, or pressure problems and can protect long-term hearing.
- Atlantic Hearing Care provides urgent hearing evaluations for sudden hearing loss in Swampscott, Massachusetts.
If you wake up one morning and the world sounds wrong in one ear, whether muffled, underwater, or simply silent, do not wait it out. What you may be experiencing is sudden sensorineural hearing loss, sometimes called sudden deafness or SSHL. It is one of the few hearing conditions audiologists treat as a true emergency, because the window for effective treatment is narrow, and every day of delay reduces the chance of a full recovery.
This article explains what SSHL is, what causes it, how it is distinguished from far more common (and far less urgent) problems like earwax or congestion, and why getting an audiogram within 72 hours can change the outcome.
What Is Sudden Sensorineural Hearing Loss?
Sudden sensorineural hearing loss is defined clinically as a hearing loss of at least 30 decibels across three connected frequencies, occurring within 72 hours. In plain language, it is a rapid, often dramatic drop in hearing, almost always in one ear, that happens over hours or a few days at most.
The “sensorineural” part of the name matters. It tells us the problem is not in the outer or middle ear, where wax, fluid, or pressure can cause temporary muffling. The problem is in the inner ear (cochlea) or the auditory nerve itself. Because these structures are delicate and have limited ability to repair, treatment timing is critical.
Estimates suggest SSHL affects between 5 and 27 people per 100,000 each year, though the true number is likely higher because many cases are misdiagnosed as a clogged ear or sinus issue and never confirmed.
How SSHL Feels: Symptoms to Recognize
People who experience SSHL describe it in remarkably consistent ways. The most common signs include:
Sudden hearing loss in one ear. Around 90 percent of cases are unilateral. Many people first notice it when holding a phone to that ear or waking up and realizing one side feels silent.
A sense of fullness or pressure, like the ear needs to “pop.” This is one of the reasons SSHL is so frequently mistaken for Eustachian tube dysfunction or wax buildup.
Tinnitus. A new ringing, roaring, or hissing in the affected ear appears in roughly 80 percent of cases and often comes on at the same moment as the hearing loss.
Vertigo or dizziness. About 30 to 40 percent of patients experience spinning, imbalance, or nausea, particularly when the inner ear’s balance system is also affected.
A loud “pop” or shift in hearing. Some people pinpoint the exact moment hearing changed; others wake up with it already in place.
If any of these symptoms come on within hours or overnight, treat them as urgent, not as a wait-and-see problem.
What Causes Sudden Sensorineural Hearing Loss?
Here is the difficult truth: in 85 to 90 percent of cases, no specific cause is ever identified. These cases are labeled idiopathic SSHL, and they are diagnosed and treated based on symptoms and audiogram findings rather than a known trigger.
When a cause can be identified, it usually falls into one of the following categories.
Viral Infections
Viral infections are the most widely suspected trigger of idiopathic SSHL. Viruses associated with hearing loss include herpes simplex, varicella zoster (the chickenpox and shingles virus), mumps, measles, influenza, and certain coronaviruses. The leading theory is that viral inflammation damages the hair cells of the cochlea or interferes with blood flow to the inner ear.
Autoimmune Inner Ear Disease
In a smaller number of cases, the immune system mistakenly attacks the inner ear. Autoimmune inner ear disease can cause sudden or rapidly progressive hearing loss, sometimes in both ears, and is often associated with broader autoimmune conditions such as lupus, rheumatoid arthritis, or Cogan’s syndrome.
Vascular Events
The cochlea is supplied by a single small artery with no backup circulation. A clot, vasospasm, or microvascular event in this artery can cause an immediate drop in hearing. Risk factors include cardiovascular disease, diabetes, and a history of stroke or transient ischemic attack.
Acoustic Neuroma (Vestibular Schwannoma)
A small benign tumor on the vestibulocochlear nerve can present with sudden hearing loss in roughly 1 to 3 percent of cases. Because of this, an MRI is part of the standard workup for unilateral SSHL, even when symptoms appear to resolve.
Ototoxic Medications
Certain medications can damage inner ear structures. The most common offenders are aminoglycoside antibiotics (such as gentamicin), platinum-based chemotherapy drugs (cisplatin), high-dose loop diuretics, and large doses of aspirin or NSAIDs. Hearing loss from ototoxicity is more often gradual but can be sudden in vulnerable individuals.
Head Trauma and Barotrauma
A blow to the head, a perilymph fistula (a tear in the membranes between the middle and inner ear), or rapid pressure changes during scuba diving or air travel can cause immediate sensorineural loss.
Meniere’s Disease
The first attack of Meniere’s disease can mimic SSHL almost exactly: sudden hearing loss in one ear, vertigo, tinnitus, and aural fullness. The pattern of repeated episodes is what eventually distinguishes the two.
Why SSHL Is a Medical Emergency
Most ear problems can wait until Monday. SSHL cannot. The reason is straightforward: corticosteroid treatment is most effective when started within the first 72 hours of symptom onset. After two weeks, the chance of meaningful recovery drops sharply. After four to six weeks, it drops further still.
The American Academy of Otolaryngology’s clinical practice guideline recommends offering corticosteroids, either oral or injected directly through the eardrum (intratympanic), to all qualifying SSHL patients as soon as possible. Hyperbaric oxygen therapy is sometimes used as an add-on within the first two weeks.
Studies suggest that with prompt treatment, roughly half of patients regain some or all of their hearing. Without treatment, only about a third recover spontaneously, and many of those recoveries are partial. The ear that is silent on day one may be silent permanently if the right steps are not taken in the right window.
Why SSHL Is So Often Missed
The symptoms of SSHL overlap heavily with much more common, much less serious problems:
- Earwax impaction can muffle hearing in one ear and create pressure.
- Eustachian tube dysfunction from a cold, allergies, or a flight can make an ear feel clogged for days.
- Middle ear fluid after an upper respiratory infection feels much the same.
In practice, many SSHL patients are first told their problem is wax. They are given drops, told to wait, and only return weeks later when nothing has changed. By then, the treatment window has closed.
This is why an audiogram matters. The only reliable way to distinguish a sensorineural loss from a conductive one is a hearing test. A licensed audiologist performing standard pure-tone and bone-conduction testing can identify SSHL in under thirty minutes, and can refer immediately for medical treatment if the loss is sensorineural.
What to Do in the First 72 Hours
If you suspect sudden hearing loss in one ear, take these steps in order:
- Do not assume it is wax. A quick look in the ear by a doctor or audiologist will rule that out in seconds.
- Get an audiogram the same day or next day. This is the test that confirms whether the loss is sensorineural.
- If SSHL is confirmed, see an ENT physician promptly for corticosteroid treatment. Audiologists work directly with otolaryngologists and can fast-track the referral.
- Ask about MRI follow-up. Even if hearing recovers, imaging is recommended to rule out an acoustic neuroma.
Time is the variable you can still control. The cause of SSHL may not be reversible, but the speed of your response is.
Recovery and Long-Term Outlook
Recovery from SSHL falls into three broad patterns:
- Full recovery in roughly one-third of patients, especially those treated quickly and with mild-to-moderate initial loss.
- Partial recovery in another third, with some hearing returning but residual loss remaining.
- No meaningful recovery in the final third, particularly when treatment is delayed or the initial loss was severe.
Patients with vertigo, severe initial loss, or loss across all frequencies tend to have poorer outcomes. Patients under 40 with mild-to-moderate loss tend to do best.
If hearing does not fully return, options remain. Modern hearing aids, including CROS systems designed specifically for single-sided hearing loss, can route sound from the affected ear to the better ear, restoring spatial awareness and making conversation in groups manageable again.
When to Call Atlantic Hearing Care
If you or someone you love has noticed a sudden change in hearing in one ear within the past few days, call us. We reserve same-day and next-day audiogram appointments at our Swampscott, Massachusetts office for exactly this situation, and we coordinate directly with local ENT physicians when SSHL is confirmed.
A muffled ear may turn out to be wax. It may turn out to be a cold. But if it is SSHL, the difference between calling today and waiting a week is often the difference between hearing again and not.
Call Atlantic Hearing Care today to schedule an urgent hearing evaluation. When sudden hearing loss is on the table, the safest assumption is the one that gets you tested fastest.