Otosclerosis: What It Is, How It Affects Hearing, and How It's Treated

Imagine trying to hear your child whispering from across the room, but all you catch is silence. Or sitting in a quiet kitchen, listening to your partner talk - and realizing you can’t make out the low tones of their voice, even though they’re speaking clearly. This isn’t just aging. It’s otosclerosis - a hidden problem in the middle ear that slowly steals your ability to hear, especially the deeper sounds most people take for granted.

What Exactly Is Otosclerosis?

Otosclerosis is not a tumor. It’s not an infection. It’s a glitch in bone remodeling. Normally, the bones in your middle ear - the malleus, incus, and stapes - move freely to carry sound vibrations from your eardrum to the inner ear. The stapes, the smallest bone in your body at just 3.2mm long, is the one that gets stuck. In otosclerosis, abnormal bone starts growing around the stapes, fusing it to the oval window - the gateway to the inner ear. This stops it from vibrating. Sound can’t pass through. Your hearing gets muffled, especially in low frequencies.

This isn’t rare. In the UK, about 1 in 200 adults has it. That’s over 300,000 people. It’s one of the top causes of hearing loss in adults under 50. Most cases show up between ages 30 and 50, and women are far more likely to be affected - about 70% of patients are female. If someone in your family has it, your risk jumps. Around 60% of people with otosclerosis have a relative with the same condition.

How Does It Affect Your Hearing?

Unlike age-related hearing loss, which hits high pitches first - like birds chirping or children’s voices - otosclerosis targets the low end. You’ll struggle with deep voices, the hum of a refrigerator, or someone speaking softly. Whispered conversations become impossible. Phone calls are a nightmare. You might think people are mumbling, but it’s your ear that’s blocked.

Audiograms show a clear pattern: an air-bone gap of 20-40 dB. That means sounds need to be much louder to reach your inner ear. Speech discrimination is usually still good - you can understand words if they’re loud enough. That’s a key difference from other conditions like Meniere’s disease, which causes spinning dizziness and fluctuating hearing, or noise-induced loss, which wipes out high frequencies first.

In about 1 in 10 cases, the bone growth spreads into the cochlea. That’s when things get trickier. You start losing nerve-based hearing too - sensorineural loss. This is permanent. Once the inner ear is affected, hearing aids help less, and surgery won’t fix it. That’s why early diagnosis matters.

Why Does It Happen?

No one knows exactly why otosclerosis starts. But we know a lot about what’s involved.

Genetics play a huge role. Researchers have found 15 different gene spots linked to it, with the RELN gene on chromosome 7 being the strongest. If your mom or dad had it, you’re more likely to get it. But genes alone don’t explain everything. That’s why not everyone with the gene develops symptoms.

Environmental triggers matter too. Measles virus has been tied to otosclerosis in studies. Hormones might play a part - symptoms often worsen during pregnancy, which is why women are more affected. Some research suggests fluoride might slow the bone growth, and that’s why sodium fluoride pills are being tested as a treatment.

The bone itself changes. Instead of dense, strong bone, you get spongy, blood-rich tissue that slowly hardens. On a CT scan, this shows up as small, dark spots near the oval window - about 0.5 to 2mm wide. These are the early warning signs.

How Is It Diagnosed?

Most people don’t realize they have otosclerosis until they’ve been struggling for months - or years. Many are misdiagnosed with Eustachian tube dysfunction, earwax buildup, or even stress. The average delay in diagnosis? About 18 months, according to Tampa General Hospital.

The gold standard is a hearing test called pure-tone audiometry. If you have a conductive hearing loss with an air-bone gap of 15 dB or more, and your speech understanding is still above 70%, otosclerosis is likely. A tympanogram will show normal eardrum movement - which rules out fluid or pressure issues. If the audiogram is unclear, a high-resolution CT scan of the temporal bone can reveal the abnormal bone growth around the stapes.

It’s not something your GP can diagnose. You need an ENT specialist - specifically an otologist who’s trained in ear surgery. That’s why so many people wait. Primary care doctors aren’t trained to spot subtle hearing patterns. If you’re under 50 and your hearing’s getting worse, especially with low-pitched sounds, ask for a referral.

Treatment Options: Hearing Aids vs. Surgery

You have two real options: hearing aids or surgery. Neither cures the bone growth, but both restore hearing.

Most people start with hearing aids. They’re non-invasive, reversible, and work well - especially for low-frequency loss. Modern digital aids can amplify the specific frequencies you’re missing, making voices clearer without cranking up background noise. About 65% of diagnosed patients choose this route first. But hearing aids don’t stop the disease. The bone keeps growing. Over five years, untreated otosclerosis can worsen hearing by 15-20 dB. That’s the difference between hearing a whisper and not hearing it at all.

Surgery - stapedotomy - is the next step. It’s not risky, but it’s not simple. A surgeon uses a microscope to remove part of the stapes and replace it with a tiny titanium prosthesis. This lets sound vibrate again. Success rates? 90-95% of patients get their hearing back to near-normal levels. In 92% of cases, the air-bone gap closes to within 10 dB. That means you’re hearing like you did before the problem started.

The new StapesSound™ prosthesis, approved by the FDA in March 2024, has a titanium-nitride coating that reduces scarring. Early results show 94% success at one year - better than older models.

But surgery isn’t perfect. About 1% of patients end up with sudden, permanent sensorineural hearing loss - a devastating outcome. That’s why informed consent is critical. Your surgeon must explain this risk clearly. Also, if you’ve had a failed surgery before, revision rates drop to 75%. First-time surgery is your best shot.

Who Should Consider Surgery?

You’re a good candidate if:

• Your hearing loss is 30 dB or worse
• You’ve tried hearing aids and they’re not enough
• Your speech understanding is still strong
• You don’t have active inner ear involvement
• You’re in good overall health

Age isn’t a barrier. I’ve seen 60-year-olds do great with stapedotomy. But if your hearing is already dropping fast in high frequencies, surgery won’t help much. That’s when hearing aids - or even cochlear implants - become the better choice.

What About Medications and Alternative Treatments?

There’s no pill that reverses otosclerosis. But sodium fluoride has shown promise in slowing it down. A 2024 study with 120 patients found fluoride reduced hearing loss progression by 37% over two years. It’s not a cure, but for people who aren’t ready for surgery - or who have early-stage disease - it’s a tool. It’s usually taken as a daily tablet, and side effects are mild: stomach upset, joint pain.

Some people try supplements like magnesium or zinc. No solid evidence supports them. Acupuncture? No data. The only proven, science-backed options are hearing aids and surgery.

What’s the Long-Term Outlook?

The good news? Otosclerosis doesn’t cause total deafness. Even without treatment, most people retain enough hearing to communicate. But it gets worse over time. Left alone, you’ll lose more of the low-end hearing, then possibly start losing higher pitches too.

Surgery gives you back your hearing - and keeps it stable. Most people don’t need another operation. The prosthesis lasts a lifetime. You’ll still need annual hearing checks to monitor for any new changes.

The bigger challenge? Fewer surgeons are doing stapedotomies now. Since 2018, the number of procedures has dropped 15%. Younger ENTs are focusing on cochlear implants and newer tech. That means finding a skilled otologist can be harder. In the UK, only a handful of hospitals have surgeons with the right experience.

Living With Otosclerosis

It’s not just about hearing. It’s about connection. One patient on Reddit said, “I thought my husband was ignoring me. Turns out, he was talking - I just couldn’t hear the low tones.” That’s isolation. That’s loneliness.

Tinnitus is common - 80% of people with otosclerosis have ringing in their ears. For 35%, it’s bad enough to disrupt sleep. Managing that takes time. Sound therapy, white noise machines, and counseling help.

Support groups matter. The Hearing Loss Association of America has over 1,200 members with otosclerosis. Sharing stories, tips, and frustrations makes a difference. You’re not alone.

What’s Next for Otosclerosis?

Researchers are working on genetic screening. Within five years, we might be able to test people with a family history and predict who’s at high risk - before symptoms start. That could mean early fluoride treatment, or even preventive monitoring.

New prostheses are being tested. Some use bioactive materials that encourage healthy bone growth around the implant. Others are designed to be inserted through the eardrum without drilling - less invasive, faster recovery.

For now, the best thing you can do is get tested if you’re noticing low-pitched hearing loss. Don’t wait. Don’t assume it’s just aging. Otosclerosis is treatable. And with the right care, you can hear again - clearly, fully, and for years to come.