Many of us ask the digital companions in our homes, whether it’s Amazon’s Alexa, Apple’s Siri or Google Assistant, to handle innocuous tasks such as setting a timer and playing music. What we may not realise is that, in some instances, there might be a person listening in, too. Whistleblowers recently said they had listened in on Siri recordings and Alexa activations that inadvertently recorded couples having sex and criminals making drug deals. In the tech industry, it’s an open secret that artificial intelligence isn’t all that smart yet. It takes lots of people manually sifting through data to train the computing systems. That means humans occasionally cull through voice recordings to train Alexa, Siri and Google to understand the nuances of speech, such as distinguishing “Austin” from “Boston,” or “U2” from “YouTube.” But tech companies have been opaque in disclosing these practices to us.

What can we do to protect our privacy with these smart assistants? Here’s a comprehensive guide.

Curtail data share

Among smart assistants, Alexa has the most comprehensive and straightforward set of privacy controls. Here’s how to opt out of human vetting:

• Open the Alexa app on your smartphone and tap Settings and then select Alexa Privacy.
• Tap Manage How Your Data Improves Alexa.
• For the control that says Help Improve Amazon Services and Develop New Features, toggle the switch to the off position.
• Here’s how to delete your voice recordings:
• In the Alexa Privacy menu, select Review Voice History.
• In date range, select the time frame of recordings you want to delete, such as All History.
• Tap Delete All Recordings for All History.

Here are other precautions to take:

• Alexa devices include a physical button to disable their microphones. Hit it whenever you are having sensitive conversations.
• Some Alexa devices, such as the Echo Spot alarm clock, have a built-in camera. To disable say, “Alexa, turn the camera off.” If you still feel uncomfortable, buy a cheap webcam cover that can slide over the lens.

Delete Siri recordings

Siri is the most lacking in privacy controls, and the process to manage user data is the least straightforward. There is no ability to review Siri recordings associated with your account, and deleting recordings is cumbersome. Siri does take some steps to mask your identity. When you make requests with an iPhone, for example, the device associates those with a random identifier instead of your Apple account ID. To reset that random identifier, you can turn off Siri and then turn it back on.

Here’s how to disable Siri on an iPhone to erase data and reset your identifier:

• Open the Settings app, tap General, then Keyboards. In the Enable Dictation control, switch it to the off position.
• Return to the Settings app. Select Siri & Search. Then disable the switches for Listen for “Hey Siri” and Press Side Button for Siri. You will see a message asking if you want to disable Siri, which will remove your data from Apple’s servers. Tap Turn Off Siri and your Siri history will be deleted.
• To re-enable Siri, go back to each of those settings and turn them back on.

Some of the sensitive recordings uploaded to Siri appeared to have come from unintentional activations, like when the crown of the Apple Watch was pressed down by accident, which summoned the assistant. To prevent this, disable the Siri side button on the iPhone. In the Settings app, tap on Siri & Search, then toggle off Press Side Button for Siri. This will simultaneously disable the shortcut on the watch.

Privacy on Google

Google offers some controls for tweaking privacy settings for Google Assistant on Android phones and Google Home smart speakers, among other products.

While Google’s human review program is suspended, you can still make sure you’re not a part of it by opting out. The search company lets you automatically delete Google Assistant requests made after a period of time.

Here’s how to disable human reviews:

• Visit Google’s web tool called Activity controls.
• Scroll down to Voice & Audio Activity. Toggle this switch off.
• Here’s how to set your recordings to automatically delete:
• Again, visit Google’s Activity controls web tool.
• Under Web & App Activity, click Manage Activity.
• Click Choose to Delete Automatically. Then click Keep for three months then delete automatically.