Noise‑cancelling headphones promise a kind of modern magic: tap a button, and the world fades away. For many people, that promise is what sells the product. But the moment you step into a busy café or open office, reality hits. You can still hear conversations. You can still hear clattering dishes. You can still hear the world.
It’s not your imagination — and it’s not that your headphones are underperforming. The truth is more nuanced, and understanding it can completely change how you think about ANC and how you use it.
Overview
Noise‑cancelling headphones don’t block every sound — especially voices and sharp, unpredictable noise.
Your ear seal plays a bigger role in quietness than most people realize.
Even with good hardware, your brain influences how quiet things feel.
Some environments will always challenge the technology more than others.
Small changes to fit and isolation can make a noticeable difference in overall performance.
ANC Was Built for a Different Kind of Noise
Active Noise Cancellation is impressive technology, but its limits are built into how it works. It listens to surrounding sound and generates an opposing wave to cancel it out. This is highly effective for low, steady, predictable noise—the drone of an airplane engine, the hum of a refrigerator, or the rumble of a bus.
But the world isn’t made of predictable noise.
Here’s what ANC can cancel well:
Low‑frequency hums
Steady, repeating patterns
Environmental “drones” like engines or HVAC systems
And here’s what ANC cannot reliably cancel:
Human voices
Clattering dishes
Barking dogs
Keyboard clicks
Sudden, sharp sounds
These sounds don’t follow patterns, so the processor can’t anticipate them. By the time the microphones detect the sound and the processor responds, the noise has already reached your ear.
This is why your headphones feel amazing on a plane but underwhelming in a coffee shop.
The Part No One Talks About: Your Ear Seal
Here’s the real secret behind noise cancelling performance — and the reason two people with the same earbuds can have completely different experiences.
ANC is only half the equation. The other half is passive noise isolation, which comes from the physical seal in your ear.
If your ear tips don’t seal properly:
High‑frequency noise leaks in
ANC can’t cancel what it can’t “hear”
Voices and clatter cut through easily
The overall effect feels weak or inconsistent
This is also where materials matter. Memory foam expands to the shape of your ear canal, filling gaps that silicone can’t. That deeper, more adaptive seal reduces the noise the system can’t touch — especially voices and sharp sounds.
Your Brain is Part of the Equation
Even when ANC and passive isolation are working well, your brain still shapes how quiet things feel. We’re naturally tuned to prioritize voices and sudden sounds, so certain noises can stand out even in a reduced sound environment.
This isn’t a flaw in the headphones—it’s how human hearing is wired. In some cases, this adjustment can even feel like slight pressure or a “vacuum” sensation. It’s simply your brain adapting to an unfamiliar soundscape.
Some Environments Will Always Win
There are places where no system — not even the most expensive one — can create true silence.
These include:
Busy cafés
Open offices
Restaurants
Construction zones
Kids’ play areas
These environments are full of unpredictable, high‑frequency noise. The technology wasn’t built for that, and it never could be.
A better seal helps, but even then, some environments will always be challenging.
Why Performance Feels Inconsistent Day to Day
If your headphones feel excellent one day and underwhelming the next, it’s usually not the technology changing—it’s your seal.
Small shifts in fit can happen without you noticing. For example:
- Ear tips may sit slightly differently in the ear canal
- Sweat or moisture can reduce grip
- Silicone tips can soften or lose structure over time
- A different insertion angle can break the seal
- Temperature changes can subtly affect material fit
Because passive isolation is such a critical part of the system, even minor changes can noticeably impact performance.
Memory foam tends to be more stable in this regard, as it expands to fill the ear canal more consistently. That’s why many listeners describe it as “unlocking” the performance their earbuds already had.
So What Actually Makes ANC Feel Better?
Not new headphones. Not a firmware update. Not a different ANC mode.
It’s the seal.
A proper seal reduces the noise the system can’t touch and gives the technology a stable foundation to work from. This is why so many people report that switching to foam tips — especially ones designed to adapt to the ear — makes their headphones feel like a completely different product.
If you want a simple upgrade, foam ear tips can make a noticeable difference. Comply's memory foam ear tips expand to your ear shape, giving the system a better foundation to work from without changing anything about your headphones.
The Bottom Line
Your noise‑cancelling headphones aren’t failing — they’re just misunderstood.
The technology reduces low‑frequency noise.Your ear seal blocks high‑frequency noise.Your brain interprets the rest.
When all three work together, you get the quiet you were expecting. And most of the time, the biggest improvement doesn’t come from upgrading your headphones — it comes from upgrading the fit. In most cases, better noise cancelling doesn’t come from better headphones—it comes from a better seal.
Why doesn’t ANC block out all noise?
Active Noise Cancellation is designed to reduce low‑frequency, predictable sounds like engine hums. It cannot fully cancel unpredictable noises such as voices, clattering dishes, or sudden sharp sounds, which is why some noise still comes through.
Does the fit of my earbuds affect ANC performance?
Yes. A proper ear seal is essential for effective noise reduction. If sound leaks into your ear canal, the system can’t cancel it. A deeper, more adaptive seal improves isolation and makes noise‑cancelling feel stronger.
How can I make my ANC headphones feel quieter?
Improving the physical seal in your ear is the most effective way to enhance performance. Using ear tips that conform to your ear shape—such as memory foam—helps block high‑frequency noise that the technology can’t cancel on its own.
Do Comply ear tips improve ANC performance?
Yes. Foam ear tips create a deeper, more adaptive seal in the ear canal, which blocks high‑frequency noise that the technology can’t cancel on its own. This often makes noise‑cancelling feel noticeably stronger and more consistent.
Our Mission
To protect & preserve hearing while transforming the way the world listens.
