What is the most common cause of unilateral hearing loss?

Unilateral hearing loss means reduced hearing in one ear while the other stays relatively normal. There is no single cause, but a very common and easily resolved one is earwax blocking the ear canal. Because causes range from simple to more significant, one-sided hearing changes are always worth having checked rather than ignored, and identifying the reason is usually straightforward once your ears are examined.

What commonly causes hearing loss in one ear?

Some of the more frequently seen causes include:

• Earwax build-up that blocks the ear canal, often the simplest cause to resolve.
• Middle-ear infection or fluid, which can follow a cold and often settles over time.
• Sudden sensorineural hearing loss, an unexplained drop in inner-ear hearing that is treated as urgent.
• Meniere's disease, which can involve fluctuating hearing, a full feeling and vertigo.
• Noise exposure concentrated on one side, for example from a firearm or machinery.
• Acoustic neuroma, a rare, non-cancerous growth on the hearing nerve that can cause gradual one-sided loss and tinnitus.

Because these vary so much in cause and management, working out which one applies to you is what matters most.

Why does one-sided hearing loss deserve attention?

Losing hearing in one ear can make it harder to tell where sounds are coming from and to follow conversation in noisy places, since your brain relies on both ears working together. Beyond the practical impact, a new one-sided loss can occasionally be the first sign of a condition that benefits from early assessment. That is why audiologists and GPs generally take it seriously rather than waiting to see if it passes on its own.

How might it affect everyday listening?

With hearing coming mainly from one side, many people notice they turn their "good ear" toward the speaker, struggle to locate a voice in a crowd, or find group conversations and phone calls more tiring. Traffic and safety cues can be harder to place, too. These day-to-day effects are a common reason people decide to get their hearing checked, and understanding them helps explain why support can be worthwhile even when one ear hears well.

When should you seek help quickly?

It is wise to see a GP or audiologist promptly, ideally within a day or two, if hearing in one ear drops suddenly, especially if there is no obvious blockage. Also seek advice if one-sided hearing loss comes with any of the following:

• Ringing (tinnitus) in the affected ear.
• Dizziness, unsteadiness or vertigo.
• Ear pain, discharge or a feeling of pressure.
• Facial weakness or numbness.

Sudden sensorineural hearing loss in particular is treated as a medical urgency, because early care may improve the chance of recovery in some cases.

How is the cause identified?

A hearing assessment can measure the hearing in each ear separately and help work out whether the loss is conductive, such as from wax or fluid, or sensorineural, involving the inner ear or nerve. Tests may include an audiogram and tympanometry, and your audiologist may refer you to a GP or ear specialist if further investigation is warranted. Hearing Help is an independent clinic at Newport Marketplace on the Redcliffe Peninsula, and no referral is needed to book a hearing assessment. If you have noticed a change in one ear, having it checked is a simple, sensible step that either brings reassurance or points you toward the right next move.