Sudden Sensorineural Hearing Loss (SSNHL) – All You Need to Know

Article contributed by Duncan Collet-Fenson, audiologist and managing director at Aston Hearing Services.

SSNHL Background

Sudden sensorineural hearing loss (SSNHL) affects between 5-30 people per 100,000 every year. Yet, despite the severity of this condition, it is little known within the audiological community and even less so in wider medical circles.

Sadly, immediate medical help is often not sought because the symptoms of SSNHL can mistakenly be put down to a temporary blockage caused by wax or fluid.

However, these symptoms may also be a result of SSNHL which is a medical emergency. Therefore all types of sudden hearing loss must be checked quickly in order to rule out anything serious.

What is SSNHL?

SSNHL, also known as sudden deafness, is defined as a noticeable drop in hearing (of at least 30 decibels in more than three frequencies) over a short period of time.

It usually affects just one ear, though it can occur in both. It can affect anyone at any time, though commonly affects people between the ages of 30-60.

SSNHL Symptoms

You may notice a “pop” in the ear before the hearing disappears, or it may fade away over a few hours.

The hearing loss may only be apparent when you try to use the phone with the affected ear.

SSNHL may also be accompanied by vertigo (dizziness), tinnitus (ringing in the ear) or a feeling of fullness in the ear.

What Should I Do if I Suddenly Lose My Hearing?

SSNHL is a medical emergency. It can result in permanent hearing loss and requires swift attention. If you suspect you have experienced SSNHL, seek immediate medical advice from an audiologist, or go straight to A&E or an ENT department. The sooner you receive treatment, the better your chances are of recovery.

Be sure to request an emergency audiogram (hearing test) – this can show evidence of SSNHL and will rule out other possible causes such as ear wax.

Like any hearing loss, SSNHL is invisible. You may otherwise look well, so you may need to emphasize to healthcare workers the urgency of the situation.

How is SSNHL Treated?

Though around 50% of people recover within two weeks without treatment, any sudden drop in hearing should be treated as an emergency.

SSNHL is commonly treated with a course of high dose oral steroids (pills) or, in some cases, steroid injections into the ear. Treatment with steroids should be offered, providing there are no medical reasons for you not being able to take it.

It is recommended that SSNHL be treated within 2-3 days of the initial loss of hearing to achieve the best possible outcome. Waiting even just two weeks for medical advice may mean you miss the opportunity for steroids to potentially improve your chance of recovery.

Your ENT consultant may want to do further follow-up tests. Hearing assessments should be repeated to monitor progress or recovery.

Why Does SSNHL Happen?

SSNHL is thought to have various causes, including viral infections, blood circulation problems, head trauma, benign tumours on the hearing and balance nerves, or autoimmune disease.

In most cases, the exact cause is never found, which makes prevention much harder. Only 10% of those diagnosed have an identifiable cause.

Can You Protect Against SSNHL?

There are no clear-cut ways to prevent SSNHL, but protecting your everyday health can also help protect your ears.

Things you can do to take care of your hearing include the following:

• If you work or spend prolonged periods of time in a noisy environment, always use hearing protection.
• Always wear a helmet when playing contact sports or riding a bike.
• Keep a check on your blood pressure. High blood pressure may cause damage to the tiny blood vessels in your ears, leading to hearing loss.
• Seek medical attention if you start experiencing tinnitus (ringing in the ear) or if your tinnitus changes in tone.

Who is Most Likely to Experience SSNHL?

If you have recently experienced any of the following conditions, you may be at increased risk of SSNHL:

• Trauma to the head
• Ear infection
• Blood circulation issues
• Ménière’s disease 
• Neurological disorders such as multiple sclerosis

However, because SSNHL can occur without any warning, it is important that you take any sudden loss of hearing seriously.

As a Hearing Professional, What Should I Do if I Suspect a Case of SSNHL?

Prompt action based on audiological results is the key to assisting a client with SSNHL. As a clinician, it is imperative to rule out any conductive reason for a reduction in hearing by performing the following checks and tests:

• A thorough inspection of the ear, ear canal, tympanic membrane, ideally captured with video otoscopy.
• Tympanometry to establish compliance of the middle ear.
• Pure Tone Audiometry, with Air Conduction and Bone Conduction thresholds (with masking where appropriate.)

Once a case of SSNHL has been identified, it should be treated as a medical emergency. The clinician should help the client to access the correct medical treatment as quickly as possible. 

The audiological data gathered from the otoscopy, tympanometry and pure tone audiometry, can be used to collate a medical referral letter. The client can then take this letter to A&E or their GP, depending on the time of day and geographical proximity.

Example of a referral letter for medical intervention for SSNHL:

After treatment, another audiogram should be performed to determine the amount of hearing remaining. An MRI can help clinicians check for a possible underlying cause of SSNHL, such as a neurological condition or acoustic neuroma.

A Final Note

Due to the time-sensitive nature of SSNHL and restrictions in accessing audiological services, the number of cases of SSNHL may be under-reported.

Knowledge-sharing between both audiological professionals and inter-disciplines may help in greater understanding and prompt access to correct diagnosis and intervention.

Acknowledgements:

Thank you to Duncan Collet-Fenson, audiologist and Managing Director at Aston Hearing Services, for this contribution.