Single-Sided Deafness: CROS and Bone-Anchored Hearing Options Explained

Imagine sitting in a crowded restaurant. Everyone is talking, laughter rings out, and the clatter of dishes fills the air. You can hear the person across from you just fine - but when someone speaks from your left side, their voice disappears. Not muffled. Not distant. Gone. That’s the reality for people with single-sided deafness (SSD), a condition where one ear has little to no hearing, while the other works normally. It’s not just inconvenient - it makes everyday life a constant struggle to catch words, locate sounds, and stay engaged. About 4 to 5 out of every 100,000 people develop SSD each year, according to the American Academy of Otolaryngology-Head and Neck Surgery. And while many assume hearing aids won’t help, that’s not true. Two main technologies - CROS and bone-anchored hearing devices - can restore balance to your hearing. But which one is right for you?

What Is Single-Sided Deafness?

Single-sided deafness means you have near-total hearing loss in one ear, but normal or near-normal hearing in the other. It’s not just being a little hard of hearing on one side. This isn’t mild hearing loss. It’s often complete loss - like turning off a speaker. You might have lost hearing suddenly after an infection, trauma, or surgery. Or it could creep in slowly due to a tumor, Meniere’s disease, or genetics. Whatever the cause, the real problem isn’t the deaf ear. It’s what happens when sound tries to reach your good ear.

That’s where the head shadow effect comes in. High-pitched sounds - like “s,” “t,” or “th” - can’t bend around your head. If someone speaks on your deaf side, those sounds get blocked. Your brain misses them. In noisy places, this makes understanding speech nearly impossible. You might nod along, pretending you heard, but you’re guessing. And because your brain expects two ears to work together, it gets confused. You can’t tell where a car is honking, a door is slamming, or a child is calling your name. It’s exhausting. And it’s isolating.

CROS Hearing Aids: Wireless Sound Routing

CROS stands for Contralateral Routing of Signals. It’s a non-surgical solution. One tiny hearing aid sits on your deaf ear. It picks up sound - voices, music, traffic - and wirelessly sends it to a second hearing aid on your good ear. Think of it like a Bluetooth speaker for your brain. Modern CROS systems, like Phonak CROS Marvel, Oticon CROS Free, and Signia CROS Pure 312, use Bluetooth or magnetic signals to transmit sound in real time. No wires. No visible cords. Just two small devices, one on each side.

Here’s the catch: CROS doesn’t fix your deaf ear. It just moves sound from one side to the other. So you’re still hearing with only one ear. But it helps. Studies show CROS reduces the head shadow effect by 8-10 decibels. That means you catch more words from your blind side. In quiet rooms, many users report feeling like their hearing is “balanced” again.

But CROS has limits. In noisy places - like a busy street or a restaurant - it can make things worse. Why? Because it picks up all the noise from your deaf side and sends it to your good ear. That includes clattering plates, background music, and people talking behind you. Your brain gets overloaded. One 2022 study found CROS users actually understood speech 1.2 dB worse than when they weren’t using the device, when noise came from their deaf side. That’s not a typo. It’s real. And it’s why many users abandon CROS. One Reddit user said, “I love not having surgery, but voices from my deaf side sound like they’re inside my head. And I’m changing batteries every two days.”

CROS systems are cheaper - $2,500 to $4,000 for the pair. No surgery. No recovery. You can try one for two weeks before buying. Fitting takes 2-3 visits over 4-6 weeks. Most people adapt in under two weeks. But battery life? Short. Size 13 or 312 batteries last only 2-3 days. And if the device fails, repairs are quick - usually under 3 business days.

Bone-Anchored Hearing Devices: Sound Through Bone

Bone-anchored hearing devices (BAHD), also called bone conduction systems, work differently. Instead of sending sound through the air, they send vibrations directly through your skull bone to your inner ear. The sound bypasses your outer and middle ear entirely. That means your good ear doesn’t have to work harder. It just receives the signal cleanly.

There are two types: percutaneous and transcutaneous. Percutaneous systems - like Cochlear Baha - have a titanium implant screwed into your skull behind the ear. After 3-6 months of healing, a sound processor clips onto a small abutment sticking out of your skin. Transcutaneous systems - like Oticon Medical Ponto 5 SuperPower or MED-EL Bonebridge - use magnets or a fully implanted transducer under the skin. No hole. No abutment. Just a small external processor that sticks to your skin with a magnet.

BAHDs don’t just route sound. They restore natural sound quality. Because the sound travels through bone, it’s clearer, more direct, and less distorted. In a 2015 study, 3 out of 8 SSD patients preferred BAHD over CROS for sound quality. Users report wind noise is less annoying. Voices sound more natural. And because your ear canal stays open, you don’t get the “plugged-up” feeling that comes with traditional hearing aids.

But there’s a trade-off: surgery. The procedure takes about 45 minutes. You’ll need a CT scan first to check your skull thickness (must be at least 3.5 mm). Then comes recovery. Skin irritation around the abutment happens in 15-63% of percutaneous users. One user on a hearing forum said, “I get skin infections twice a month. I need antibiotic cream. But the sound? Worth it.” Transcutaneous systems reduce this risk, but they’re slightly less powerful - about 10-15 dB less amplification than percutaneous.

Cost is higher. The device alone runs $4,000-$8,000. Surgery adds $3,000-$7,000. Insurance sometimes covers it, but often doesn’t. Recovery takes months. But once you’re healed, the processor lasts 5-7 days on a single size 675 battery. Repairs? Slower. Specialized centers handle them - average turnaround is nearly two weeks.

Which One Works Better?

Let’s cut through the noise. Neither CROS nor BAHD gives you true two-ear hearing. Both are workarounds. But they do different things well.

Here’s what the data shows:

Here’s the truth: if your good ear is perfectly healthy and you want to avoid surgery, CROS is a smart first step. It’s low-risk, low-cost, and easy to try. But if you’re in a noisy job - construction, teaching, hospitality - or you’re frustrated with CROS’s poor performance in restaurants, BAHD delivers real, measurable improvement. The CINGLE trial showed BAHD users had better speech understanding than CROS users when noise came from their deaf side. And while neither system restores full 3D hearing, BAHD comes closer.

One big surprise? Dropout rates. In a 2022 study, nearly half (46%) of CROS users stopped using their device after a year. Only 7% of BAHD users quit. Why? Because CROS promises more than it delivers. It makes you think you’re hearing normally. But in the real world - where noise is everywhere - it often makes things harder.

Who Should Choose What?

There’s no one-size-fits-all answer. But here’s a simple guide:

• Choose CROS if: Your good ear has perfect hearing (pure-tone average ≤ 25 dB HL), you’re not in a noisy job, you hate the idea of surgery, and you want to test the waters. It’s a trial run.
• Choose BAHD if: Your good ear has mild hearing loss (up to 45-55 dB HL), you’re active (runner, cyclist, gym-goer), you’re tired of changing batteries every few days, and you want clearer, more natural sound - even if it means surgery.
• Consider a cochlear implant if: You’ve tried both and still struggle. New FDA guidelines (January 2024) now support cochlear implants for SSD after 6 months of failed CROS or BAHD use. CI gives the best sound localization - 18.3° error vs. 35° for CROS.

Also, watch for tinnitus. Nearly 78% of SSD patients have ringing in the ears. New CROS models like Signia CROS Pure 312 now include built-in tinnitus therapy. BAHDs don’t. If tinnitus is a problem, that could tip the scale.

What’s Next for SSD Treatment?

The field is changing fast. Wireless CROS systems are getting smarter. Phonak and Oticon now use AI to filter background noise. Cochlear’s 2024 Baha 7 Smart Sound Processor uses machine learning to adapt to your environment. But the biggest shift is toward cochlear implants. Once considered a last resort, CI is now being recommended earlier. The CINGLE trial showed CI users had the best spatial hearing - by far. And surgical techniques are becoming less invasive.

Meanwhile, CROS is still the most common first choice. Sixty-five percent of new SSD patients start with CROS, according to the American Academy of Audiology. But the tide is turning. BAHD adoption is growing at 8.7% per year. And as transcutaneous systems improve - with no skin holes, better batteries, and stronger signals - more people will skip CROS entirely.

One thing’s clear: you don’t have to live with single-sided deafness. You don’t have to guess at conversations or feel left out. There are real, proven solutions. The question isn’t whether to treat it. It’s which path fits your life.

Final Thoughts

Single-sided deafness isn’t just a hearing problem - it’s a communication problem. It steals your confidence in crowds, your peace in quiet rooms, your sense of safety on the street. You don’t have to accept that. CROS and bone-anchored devices are not magic. But they’re real tools. One is simple, safe, and affordable. The other is more involved, but delivers more natural hearing. The right choice depends on your lifestyle, your ears, and your goals. Talk to a specialist. Try a CROS. Ask about BAHD. And don’t let silence win.