Every word. Without the fuss.

Rechargeable in-ear amplifiers for everyday listening. Discreet, ready in minutes, and priced so that trying them is not a decision.

Shop Certus One
  • Honest by designSold as what it is: an amplifier, never a medical claim
  • 90 days at homeReal dinners, real phone calls, or your money back
  • 2-year guaranteeCovers faults. A human answers the email
  • Free deliveryDispatched 7 days a week, 2pm GMT cutoff

Certus means sure

Everyday listening you can be certain of, without the gadget nonsense.

Certus is Latin for sure, settled, proven. We make rechargeable in-ear amplifiers for everyday listening: discreet, simple, ready in minutes. Then we give you 90 days to hold us to the name.

Where we sit

There was nothing honest in the middle. So we built it.

Above us, a building full of appointments you pay for. Below us, gadgets that make the kettle as loud as your grandson. We are the row without a catch.

Below

Bargain-bin gadgets

£7 to £90

Ten to ninety pounds. They boost every noise at once, whistle, and end up in a drawer. No support, nobody to email.

Certus

Certus One

£149

A rechargeable in-ear amplifier for everyday listening, delivered to your door. 90 days at home to prove it. A two-year guarantee behind it.

Above

Private audiology

£1,000 to £3,000+

Months of appointments, a waiting room, and a price that needs a family meeting. You are paying for the building.

Above

The NHS route

Free

Genuinely good, and genuinely slow. A waiting list, limited choice, and still a diary full of appointments.

The Certus One charging case open on a soft green-grey surface, both in-ear devices resting inside, with one device beside a coin to show the scale
Rechargeable amplifier

Certus One

A rechargeable in-ear amplifier for everyday listening, sold as a pair with a pocket charging case. It sits deep enough that nobody has to know it is there.

£149 £299 Save £150 a pair
  • 16 hours per charge, 60 hours with the case
  • 2 grams. You forget it is in
  • 12 tips in 3 sizes, fits first time
  • USB-C. No batteries to fiddle with
Try Certus One Risk-Free

90-day money-back · 2-year guarantee · free delivery

How it works

You hear the words, not the room.

Cheap gadgets turn everything up at once, which is why the kettle drowns out your grandson. ClearVoice™ SpeechLift works the other way round.

  1. 01

    It finds the voice

    Speech lives in a narrow band of frequencies. ClearVoice™ listens for that band and separates it from the room around it.

  2. 02

    It lifts the words

    The speech band comes up. The clatter, the traffic and the kettle stay where they are, so you hear the sentence instead of the surroundings.

  3. 03

    It settles down

    No app to fight with, no setup to learn. Put them in, and they get on with it from the first conversation.

Our standard

What we will and will not claim.

Plenty of sellers dress a gadget up as a medical device. We would rather tell you exactly what this is, and let the 90 days do the arguing.

  • It is an amplifier, and we say so

    Certus One is a rechargeable in-ear amplifier for everyday listening. We do not call it a medical device, because it is not one, and you deserve to know which you are buying.

  • It is for everyday listening

    Conversation, television, the telephone. If you are worried about your hearing itself, that is a conversation for a doctor, not a checkout page.

  • It is not a cure, and not a diagnosis

    It makes speech easier to follow. It does not treat anything. Sudden hearing loss needs a doctor, not a purchase.

An open Certus One case resting on a wooden side table beside a pair of reading glasses and a folded newspaper, lit by a warm lamp in a lived-in room

Why we exist

Certus started with a drawer.

In it: a pair of devices that cost more than a family holiday, worn twice, abandoned. And next to that drawer, a father who had quietly stopped joining conversations. Who laughed a half-second after everyone else, because he was copying the room.

The clinics wanted thousands to try again. The cheap gadgets whistled and made the kettle as loud as the conversation. So we built the in-between, and named it after the only thing that matters when it is your money and your ears.

Read the whole story →

In the box

Everything, first time. Nothing to order later.

No missing part, no accessory upsell three days after it arrives. You open it once and you are ready.

  • A pair of devicesLeft and right, sold together. Never one ear at a time
  • Pocket charging caseFour more full charges away from a plug socket
  • 12 tips, 3 sizesSo it seals properly, which is what stops the whistling
  • USB-C cableThe same cable as your phone, most likely
  • Large-print guideWritten for a kitchen table, not an engineer
Overhead view on pale linen of everything included with Certus One: the closed retail box, the open charging case with both devices, twelve ear tips fanned out in three sizes, a coiled USB-C cable and a large-print quick-start card

A day with Certus

Back in the room, from the first morning.

Nobody buys these because they want a gadget. They want the dinner, the phone call and the evening to feel like theirs again.

An older man sitting in an armchair in warm afternoon light, relaxed and clearly following a conversation happening around him
Before breakfast

In before the kettle boils

Charged overnight, in before the tea is made, and nobody at the table knows they are there.

The hands of an older adult opening the Certus One box at a kitchen table in morning light, the case and ear tips visible inside
The first ten minutes

No appointment, no waiting room

Charge the case, find the tip that seals, put them in. That is the whole setup.

A couple sitting together on a sofa in the evening with the soft glow of a television, both comfortable, a mug of tea on the side table
Evenings

The television, at a normal volume

One volume that suits the whole room, and everybody gets their evening back.

A close macro view of one Certus One device resting on the edge of its open charging case, the wordmark on the lid softly out of focus behind it
Up close

Two grams, and deep in the ear

Small enough that the question never comes up, and light enough that you forget it is in.

Straight answers

The questions people actually ask.

Will people see them?

No. Certus One sits deep in the ear canal in a matte shell that follows your ear, not against it. Most people never notice, including the person you are talking to.

What exactly is this?

A rechargeable in-ear amplifier for everyday listening. It makes speech easier to follow at the dinner table, on the phone and in front of the television. We do not call it a medical device, because it is not one.

Why is it cheaper than what a clinic charges?

Because it is a different thing entirely, sold a different way: direct to you, with no building and no appointments in the price.

Will they whistle?

Only if the tip does not seal. That is why 12 tips in 3 sizes come in the box instead of one guess. Find the seal and the whistle goes.

Do I need an app or a smartphone?

No. Put them in and they work. There is nothing to pair, download or update.

I think my hearing has changed. Should I buy these?

See a doctor first. If your hearing has changed suddenly, or only in one ear, that needs medical attention, not a purchase. We would rather lose the sale than be the reason you waited.

What if they are not right for me?

Send them back within 90 days and we refund you. No questions, no restocking fee, and a human answers the email.

Certus means sure

Ninety days to prove it. That is the whole offer.

Wear Certus One at home for 90 days: the dinners, the phone calls, the television. If it does not earn its place in your ear, send it back and we refund you.

Try Certus One Risk-Free

90-day money-back · 2-year guarantee · free delivery