Voice assistants are convenient services that allow you to check the weather, set an alarm, play music, or search for something completely hands-free. Android allows you to select among various voice assistants, such as Google Assistant, Amazon Alexa, and, if you own a Samsung phone, Bixby. However, although Android permits any app to be set as the default assistant app, it does not allow any app to respond to wake words such as “Hey Google” while running in the background. This is primarily for privacy purposes, as your phone has to continuously listen to audio via the microphone to detect the specified wake phrase. A new addition in Android 15, known as “voice activation”, has the potential to address this issue by utilizing a privacy-conscious “adaptive sensing” technology.
While examining the Android 14 QPR2 beta, we came across a concealed page for voice activation applications (displayed below). This page is located in the Settings menu, specifically under Apps and Special App Access. It enables you to choose which apps you want to provide permission for voice activation. Based on the description of the permission, voice activation enables the activation of permitted applications without the need for manual input by using voice commands. The included adaptive sensing feature guarantees that your data remains private and exclusive to you.
There is a link at the conclusion of the description that provides additional information on “protected adaptive sensing.” However, the link directs to a Google support page that is not currently active. Therefore, we are still determining the level of privacy that adaptive sensing will provide for your speech data. This probably be operated likely using Android’s Private Compute Core (PCC), which includes the system app Android System Intelligence for offline data processing and Private Compute Services for tasks that need network connectivity. In this manner, applications that require voice activation authorization would not have to handle any microphone data on their own; the PCC would detect the wake word(s) and subsequently activate the respective application. This is primarily our conjecture, however.
Upon further examination of the operating system code, we discovered a reference to a log message that connects this newly added permission and API to the functionality of detecting hot words. The log indicates that the hot word detection service will be deactivated if an app’s voice activation authorization is cancelled. We are uncertain whether this voice activation function will enable applications to be activated by bespoke wake words or merely by pre-set ones. However, there does appear to be a connection between wake words and this new functionality.
The most intriguing aspect of this innovation is that third-party apps can own the new voice activation capability. The base authorization, RECEIVE_SANDBOX_TRIGGER_AUDIO, has a protection level of “appop|privileged|signature.” The “appop” protection level indicates that the permission cannot be granted during app installation or through a runtime permission dialogue. However, it can be granted if the user goes to Android’s Special app access page, as illustrated above.
In earlier versions of Android, it was feasible for apps developed by third parties to activate when the wake phrases “OK Google” or “Hey Google” were detected. However, Google eliminated this feature in Android 12 and also applied a fix to Android 10-11, stating that it posed a security risk. The existing API and authorization used to detect and react to wake words is currently limited to system apps. However, the new voice activation permission is currently less restricted. However, this could change prior to the availability of the voice activation function.
Additional information is limited regarding this planned feature as it is still being developed and is expected to be released alongside Android 15. If Google does eventually make this voice activation capability available to third-party apps, then it might be possible for apps like ChatGPT to be activated by voice. The ChatGPT app is almost ready to include the option of being set as the default assistant app. However, even if it is set as the default assistant, you won’t be able to use ChatGPT completely hands-free as you can with Google Assistant. Android 15’s voice activation capability has the potential to make that achievable.
Amazon Alexa could also benefit from this capability if it functions as we have outlined. The app presently only reacts to the “Alexa” trigger word when it is active. A few “Alexa Built-in” phones were able to wake Alexa on any screen. However, this program didn’t last long because it needed the device maker to add Alexa wake phrase compatibility specifically. Currently, Google Assistant and Bixby are the exclusive virtual assistants on Android devices that can activate hands-free voice commands. However, this new feature in Android 15 has the potential to extend this functionality to additional services.