Sudden Hearing Loss: When Hearing Changes May Be an Urgent Concern

The Hearing Change Many People Wait Too Long On

You wake up one morning and something feels off. One ear sounds muffled. Maybe there’s a ringing you didn’t have yesterday. You figure it’s clogged, or you slept on it wrong, or it’s just allergies. You decide to wait it out.

That waiting may reduce your options for recovery.

Sudden hearing loss in one ear is one of the few hearing changes that current clinical practice guidelines identify as time sensitive. The treatment window is measured in days and weeks, not months. And many people are not aware of it until it happens to them or someone they care about.

This blog explains what sudden hearing loss is, how it may present, and why acting quickly may be helpful.

What Is Sudden Sensorineural Hearing Loss?

Sudden sensorineural hearing loss (SSNHL) is a rapid loss of hearing in one ear that develops over 72 hours or less.

Clinically, it is defined as a sensorineural hearing loss of at least 30 decibels across three consecutive frequencies, developing within a 72 hour period [1]. In everyday terms, this means a noticeable, fast drop in hearing that was not there before.

According to published research, SSNHL affects approximately 5 to 27 people per 100,000 each year in the United States, with similar patterns reported internationally [2]. The Merck Manual reports that the incidence increases with age, ranging from about 11 per 100,000 for adults under 18 to 77 per 100,000 for adults over 65 [2].

SSNHL can occur at any age, though research reports that it is most commonly seen in adults in their 40s and 50s [3]. It typically affects one ear.

Common Signs of Sudden Hearing Loss

One challenge with SSNHL is that many people do not feel like they are experiencing an urgent medical event. There is often no pain, no fever, and no clear injury. Just an ear that feels different.

Reported signs may include:

Many people first notice symptoms upon waking. Research suggests that tinnitus is reported in approximately 90% of SSNHL cases, and about 40% of patients experience some degree of dizziness [3].

Why SSNHL Is Often Missed

SSNHL is often mistaken for more common issues, such as:

Because these are so much more common, both patients and general clinicians may initially attribute the symptoms to one of these causes. Current clinical practice guidelines from the American Academy of Otolaryngology emphasize the importance of prompt recognition of SSNHL to distinguish it from more common causes of hearing changes [1].

If you experience a sudden change in hearing in one ear, it may be helpful to seek evaluation the same day if possible, and to specifically mention the possibility of sudden sensorineural hearing loss so it can be considered as part of the workup.

Why Timing May Matter

Current clinical practice guidelines describe a defined window for treatment.

The American Academy of Otolaryngology 2019 update on sudden hearing loss states that clinicians may offer corticosteroids as initial therapy within two weeks of symptom onset [1]. The guidelines also outline options for combined steroid and hyperbaric oxygen therapy within two weeks of onset, and salvage therapy options within one month [1].

Research on recovery outcomes suggests that some patients recover partially or fully with treatment, while others do not. According to the Merck Manual, recovery rates with corticosteroid treatment within two weeks are reported around 75 to 80% for patients with mild, moderate, or severe hearing loss (excluding profound cases) [2]. Studies also report spontaneous recovery rates ranging from about 32 to 65%, though not everyone recovers without treatment [4].

Because there is no way to predict which cases will recover on their own, current guidelines emphasize prompt evaluation rather than a wait and see approach [1].

What Causes Sudden Hearing Loss?

In most SSNHL cases, no specific cause is identified. Research suggests that between 71 and 90% of cases are classified as idiopathic, meaning no underlying cause is confirmed [5].

When a cause is identified, it may include:

Current guidelines recommend imaging (typically MRI) or auditory brainstem response testing to help rule out retrocochlear pathology in patients with SSNHL [1].

What To Do If You Notice Sudden Hearing Changes

If you notice a sudden hearing change in one ear, the following steps may be helpful:

If the cause turns out to be something more common such as earwax or congestion, that is useful information. If it turns out to be SSNHL, prompt evaluation supports the treatment window described in clinical guidelines.

After the Initial Evaluation

Current guidelines recommend follow up hearing evaluation at the end of treatment and within six months of completing treatment [1]. This allows the care team to track changes over time and identify any residual hearing loss or tinnitus that may benefit from further support.

If some hearing loss remains after treatment, an Audiologist can discuss options for hearing care and rehabilitation. This may include hearing aids, hearing assistive technologies, or other supportive approaches, depending on individual needs.

When To Seek Care

It may be worth seeking prompt evaluation if you experience:

Same day evaluation is often recommended when possible. Current clinical guidelines describe the initial treatment window as within two weeks of symptom onset [1].

Book a Hearing Evaluation in Etobicoke

At Toronto Hearing Services, Audiologist Lorraine Vosu provides hearing evaluations and hearing care services to patients in Etobicoke and the surrounding area. If you or a family member has experienced a sudden change in hearing, we are here to help you get answers.

To book a hearing evaluation, call (416) 233-8581 or visit our website to request an appointment.

 

Sources

[1] Chandrasekhar, S. S., Tsai Do, B. S., Schwartz, S. R., et al. (2019). Clinical Practice Guideline: Sudden Hearing Loss (Update). Otolaryngology Head and Neck Surgery, 161(1_suppl), S1 to S45. https://journals.sagepub.com/doi/10.1177/0194599819859885

[2] Sudden Hearing Loss. Merck Manual Professional Version. https://www.merckmanuals.com/professional/ear-nose-and-throat-disorders/hearing-loss/sudden-hearing-loss

[3] Comparison of Recovery Rates of Sudden Sensorineural Hearing Loss by Age Group. (2024). PMC. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11355421/

[4] Sudden sensorineural hearing loss: Recovery rates according to audiometric patterns. (2022). Acta Otorrinolaringologica Espanola. https://www.sciencedirect.com/science/article/abs/pii/S2173573522001016

[5] Sudden Sensorineural Hearing Loss Standard Procedure. Military Health System. (2024). https://health.mil/Reference-Center/Clinical-Practice-Guidelines/2024/11/25/SSNHL-Coding-Guidance–Otolaryngology