Sonic Alert vs Geemarc Bed Shakers: Which to Buy

Short answer

Sonic Alert and Geemarc build the same kind of device: a mains bedside clock with a loud tone, a flashing light and a wired shaker pad for under the pillow or mattress. The deciding factor is not which brand shakes harder, because neither publishes a vibration-force figure and nobody credibly does. It is which country you are buying in. Geemarc is the supported brand in the UK and Europe, with a two-year warranty; Sonic Alert is the US brand, with a warranty its own page says runs one to five years by model and explicitly excludes international purchases. Buy the one your market supports, and buy the shaker its maker lists for your clock. One wrinkle makes this less of a contest than it looks: in the UK, Geemarc distributes the Sonic Bomb, listing the SBB500SS on its own site.

Disclosure, and please weigh it: as of 8 August 2026 we sell a bed shaker ourselves, the EIVOI Bed Shaker Alarm Clock at $44.00, as listed 11 August 2026. Until 8 August 2026 we had none and said so across this site. We have not tested it against either brand below, both of which have decades of track record with deaf customers that we do not. Figures read on 9 August 2026.

What each brand actually sells

Sonic Alert (US) sells the Sonic Bomb and Sonic Boom clock families plus the Sonic Shaker travel unit. From their own site, 9 August 2026: Sonic Bomb SBB500SS $44.99 (reduced from a listed $72.99), Sonic Bomb Junior SBJ525SS $34.99, Sonic Shaker SBP200 $35.00, Sonic Boom SB1000SS hub $104.99, replacement Super Bed Shaker $17.99.

Geemarc (UK/Europe) sells the Wake 'n' Shake range — Star, Curve, Dynamite, Spot, Vintage and the battery Voyager — plus the SBB500SS. Geemarc publishes no prices itself, so UK figures come from retailers. On healthandcare.co.uk, 9 August 2026: Wake 'n' Shake Star £54.98 inc VAT / £45.82 ex VAT, Sonic Bomb £47.99 inc VAT / £39.99 ex VAT. Marketplace prices for both brands move constantly and often reflect imports on the wrong mains voltage; treat them as indicative only.

Shaker force: the number that decides everything, and nobody prints it

This is the specification a deaf buyer most needs and the one neither company publishes. You will see 12V on the Sonic Bomb's shaker and 6V on the Junior's, and Geemarc describes its pads qualitatively. Voltage is an electrical rating, not a measure of how hard a pad moves a mattress; that depends on the motor, the counterweight and what it is lying under. We publish no force figure for any product here, ours included, because no credible one exists.

Act on placement instead. Under the pillow is strongest and easiest to lose in the night; under the mattress is weaker but cannot be dislodged, and deep memory foam absorbs a great deal of either. Buy somewhere with a real returns window, because a fortnight of actual mornings is the only test that means anything. More in our guide to choosing a bed shaker alarm.

Connectors: do the shakers swap between brands?

Assume not. Geemarc publishes a connector for the Star: retailer listings specify a 5.5mm shaker jack plug on a 2m cable. Sonic Alert publishes no connector spec for its clock shakers, listing compatibility as a set of model numbers instead — SBB500SS, SBC575SS, SB1000, SBD375SS and others. A separate Sonic Alert shaker for Geemarc telephones is listed by the retailer Diglo with a 3.5mm plug, so the company uses more than one connector.

Two consequences. Even within Sonic Alert, shakers are not universal: the Sonic Bomb uses a 12V pad and the Junior a 6V one, and a pad that plugs in is not necessarily one the clock is built to drive. And cross-brand swaps are guesswork — a Geemarc extension lead is marketed on Amazon as suiting both the Wake 'n' Shake range and Sonic Alert clocks, but neither manufacturer publishes a compatibility statement for the other's hardware. Buy the replacement your clock's maker names.

The decibel figures disagree with each other

Geemarc publishes 95 dB spl at 1 metre for the Star, 95 dB for the Curve and up to 75 dB spl at 1 metre for the battery Voyager (geemarc.com/uk, 9 August 2026). Now the odd part. For the same model number, the SBB500SS, Sonic Alert's own site says "113 dB extra-loud alarm" and healthandcare.co.uk repeats "up to 113 decibels", while Geemarc's UK page for that identical model says 85 dB. Both read on 9 August 2026. We cannot reconcile that, and will not pick a winner between two manufacturer claims. Treat headline loudness as marketing, not measurement, especially where the measuring distance goes unstated. The same problem appears in our Geemarc vs Bellman & Symfon comparison.

If your hearing loss is significant, this whole section is decoration and the shaker does the work. Whether a given loss leaves you usable benefit from an audible alarm is a question for your audiologist, not for a product page.

Display, power and warranty

Display. Geemarc publishes the most detail: the Curve has a 4.3 x 2 inch LED screen with 0.9 x 2 inch digits, red on dark, with a three-position dimmer. The Star has a large white display with a dimmer. Sonic Alert calls the Sonic Bomb's a large red display with a five-level dimmer but publishes no size, so the Curve is the only one here where you can check digit height before ordering.

Power. Both brands' main clocks are mains units with an adapter. The Star's retailer listing specifies back-up battery capability, battery not included. Sonic Alert says the Sonic Bomb's backup secures settings during an outage, which is not the same promise as still sounding the alarm, and healthandcare.co.uk's listing for that clock does not mention backup at all. Get it confirmed in writing if a power cut must not cost you a morning. The only battery-native option is Geemarc's Voyager, on 2 x AA and 1 x AAA, also the only one that travels.

Warranty. Geemarc: two years, repair or replacement, buyer pays return postage. Sonic Alert: one to five years by model per their warranty page, with the Sonic Bomb's page stating one year, and the policy excludes unauthorised sellers and, in their words, international purchases. For a UK buyer that is the strongest argument for the Geemarc-distributed version over an import.

Who this whole category fails

Both brands' marketing skips this. Anyone sharing a bed, because a shared mattress wakes both of you and no model from either brand solves it (shakers versus wrist devices covers the alternative). Anyone who travels, since a mains clock with a cabled puck is not hand luggage. Anyone in a flat who intends to use the tone; see who extra-loud clocks actually suit. Any household including someone with photosensitive epilepsy, as several of these clocks flash bright LEDs. And very deep foam mattresses. A device also cannot fix an underlying sleep problem: if you sleep through a shaker you used to feel, raise it with a GP rather than buying a bigger motor.

Where ours fits, honestly

Our Bed Shaker Alarm Clock is $44.00, as listed 11 August 2026: a 7.5-inch LED display, a wired pad for under the pillow or mattress, dual alarms and snooze. It carries our 100-day money-back guarantee, a longer test window than a typical returns policy allows. That is the whole of the honest case. We have not measured our pad against a Sonic Bomb's or a Star's, we publish no force figure and neither do they, and both brands have supported deaf customers for decades with service networks in place. If reliability every single morning is non-negotiable, buy from them. Our wrist device, Silent Wake, is a smaller stimulus than any mattress pad and suits travel and not waking a partner, not profound deafness. More in our overview of alarm clocks for deaf and hard-of-hearing people and our UK guide, which also covers VAT relief.

Common questions

Is Sonic Alert or Geemarc better for a profoundly deaf person?

Neither brand publishes a vibration-force figure, so no honest answer ranks them on shaker strength. Decide on support instead: Geemarc gives a two-year warranty and is the supported brand in the UK and Europe, while Sonic Alert's runs one to five years by model and excludes international purchases. Buy the brand your country supports, put the pad under the pillow first, and test it for a fortnight inside a returns window.

Can I use a Sonic Alert bed shaker with a Geemarc clock?

Do not assume so. Geemarc publishes a 5.5mm shaker jack for the Wake 'n' Shake Star; Sonic Alert publishes no connector spec at all, listing compatibility as specific model numbers instead. Even within Sonic Alert the pads differ: a 12V shaker on the Sonic Bomb, a 6V one on the Junior. A plug that fits is not proof the clock can drive it properly. Buy the replacement pad your clock's manufacturer names.

Why does the same Sonic Bomb show 113 dB on one site and 85 dB on another?

Because manufacturers in this category quote loudness inconsistently. On 9 August 2026, Sonic Alert's own page for the SBB500SS said 113 dB and Geemarc's UK page for that identical model said 85 dB. Measuring distance is often unstated, and sound drops sharply with distance. Treat headline decibel claims as marketing. For significant hearing loss the figure is largely irrelevant anyway, since the shaker is what wakes you.

Which of these clocks works in a power cut?

Check before you buy, because the wording is slippery. Sonic Alert says the Sonic Bomb's battery backup secures the settings during an outage, which is not a promise that the alarm will still sound. The Geemarc Wake 'n' Shake Star's retailer listing notes back-up battery capability with the battery not supplied. Geemarc's Voyager avoids the question entirely by running on 2 x AA and 1 x AAA cells, and it is also the only genuinely portable option here.

Is Geemarc available in the US, and Sonic Alert in the UK?

Partly, and mostly through the other brand's channels or marketplaces. Geemarc distributes the Sonic Bomb in the UK and lists it on its own site, so British buyers get Sonic Alert hardware with local support. Geemarc's Wake 'n' Shake clocks appear on US marketplaces largely as imported UK versions, where mains voltage and warranty cover become real problems. Buy the locally supported brand rather than importing.

Prices and specifications read from sonicalert.com, geemarc.com/uk, healthandcare.co.uk and diglo.com on 9 August 2026 and subject to change; verify before buying. Marketplace prices vary widely and are not reflected here. We sell a bed shaker alarm clock and a wrist-worn alarm and disclosed that at the top. Nothing here is advice about your hearing; speak to an audiologist about what you can rely on hearing.