The Pozio Cradle is a phone-charging accessory with an unusual feature: It has the ability to defeat your smartphone’s microphone.
People don’t normally buy new gadgets to block functions in their old gadgets, but the capabilities of smartphones—including personal-assistant services that might be listening silently—don’t make them normal devices.
How can one gizmo prevent another’s microphone from hearing you? This vertical black frame with rounded corners employs what a FAQ for Pozio’s unsuccessful Kickstarter campaign calls “shaped, sub-audible sound.” The even more vague FAQ on Pozio’s site says this involves “patented digital signal processing”—to stop a phone in the cradle from hearing any audio.
That may sound like high-tech puffery. But when I tried a company-loaned Pozio Cradle with four phones—a Google Pixel 5a, a Samsung Galaxy S9, an iPhone 12 Pro, and an iPhone Xs—it functioned as advertised. Google Assistant, Alexa, and Siri ignored me, trying to voice-dictate in Android generated zero text, and tests of capturing speech in audio-recording apps yielded static.
A cooling fan in the cradle whirs when the blocking function operates—which, depending on whether white noise helps you sleep, could rate as a feature or a bug if you park this cradle on a nightstand. With background noise like a TV or conversation, I struggled to hear the fan.
You can disable Pozio’s blocking by pressing the button on top, which stops the fan and changes an LED stripe below a shield icon from white to blue. Or you can allow 30 seconds of phone listening by saying “Pozio stop,” which sets the LED blinking in white during that pause.
Yes, this device itself responds to voice controls. The company FAQ notes that this hardware includes neither internal storage to save anything nor internet connectivity or NFC wireless to send data anywhere.
Privacy worries—reasonable or otherwise
As Pozio’s voice-control option suggests, we’ve grown to expect that when we talk to our devices they will listen and respond. But we want that to happen only when we’ve signaled our intent, usually by saying wake words like “Alexa,” “Hey, Google,” or “Hey, Siri.”
And people continue to worry that one app in particular, Facebook, has not honored that social contract. The persistence of the unfounded idea that Facebook targets its ads by having its mobile apps listen surreptitiously says a lot about both our smartphone suspicions and the existence of companies like Pozio.
There is a history of speech-driven personal assistants mistaking speech or noises for their wake words.
And even if you credit Facebook with the phone-hacking prowess of the spyware merchants at NSO Group, this theory lacks any political logic. Facebook faces intense scrutiny by regulators around the world and has seen vast troves of internal documents exposed by whistleblowers like Frances Haugen.
There is, however, a history of speech-driven personal assistants mistaking speech or noises for their wake words, then recording conversations that could have been heard by contractors tasked with improving the accuracy of these systems. A five-month period in 2019 saw reports of this happening with Amazon’s Alexa, Google’s Assistant, and Apple’s Siri; these companies said very few recorded conversations get checked by humans in this way, and Apple added an opt-out feature to match those already at Amazon and Google. Still, voice-assistant recordings have even been sent to random strangers accidentally.
Those are risks that the Pozio Cradle can address, and since it doubles as a Qi wireless charger, it’s more practical than such earlier privacy-tech attempts as Alexagate, a noise-canceling cover for Amazon Echo smart speakers from a Brooklyn collaborative called MSCHF.
Pozio also sells smart-speaker-blocking devices: a $99 model sized for Amazon’s Echo Dot and Echo Studio, and an $89 version for older Echo Dots as well as Google’s Home Mini and Nest Mini.
None of the company’s blocking gadgets do anything for all the other internet-connected devices in and around our homes with always-on microphones, such as streaming-media players and smart displays—not to mention all the connected appliances, from refrigerators to dimmer switches to kitchen faucets, that now come built to be controlled by voice-driven personal assistants.
Smart speakers do include their own switches to block their microphones and cameras, and you can set Android and iOS to ignore their “Hey, Google” and “Hey, Siri” wake words. Because I have adjusted those settings and others, including the opt-outs for having speech recordings uploaded for human analysis, I’m comfortable doing without Pozio’s help. But did reading this paragraph make you wonder when you last used any of those options?
To judge from how many of these devices show up not just at gadget gatherings like CES but in people’s homes, it looks like many of us have already made a choice about balancing privacy and convenience. And it’s one that Pozio’s creators might not appreciate.