One of the more popular, modern conspiracy theories is that your phone is always-listening to serve advertisements. The advent of smart speakers has done nothing to stop that “theory,” but a pair of designers have now created a physical accessory to disrupt Google Home from always recording.


Project Alias (via FastCompany) is a “middle-man device” created to make smart speakers more private by obfuscating the always-listening capability. For convenience, microphones on Google Home and Amazon Alexa are always-on to pickup the hotword and begin a command.

Alias physically lays on top of a speaker’s microphone to blast “constant low noise/sound” until you say the hotword. This is intended to ensure that smart speakers never accidentally pick up other conversations.

The built-in speaker that emits white noise will then switch to a recording of the hotword so that a user’s command can proceed. Alias does feature microphones, but its creators note how processing occurs on-device with a Raspberry Pi.

The wake word detection is made with a small neural network that runs locally on Alias, which can be trained and modified through live examples. The app acts as a controller to reset, train and turn on/off Alias.

In terms of whether this is needed on the privacy front, Google and Amazon note that devices are only listening for the hotword. Meanwhile, most devices feature a physical switch to disable the microphone.

However, the more interesting use case for Alias on Google Home is custom hotwords. Google has so far signaled no willingness to allow users to change the activation phrase. Alias allows users to set a custom phrase, with the built-in speaker emitting the standard “Hey Google” when it hears your hotword.

Instructions to 3D print Project Alias and download the software are available on Github. Ultimately, it provides a second line of defense for those that feel it is needed.

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