A speaker that answers questions is also a microphone with a network connection and a retention policy. Those policies differ sharply between Amazon, Google and Apple, and the defaults favour the company’s ability to improve its speech recognition rather than your preference for a short memory.
You do not need to unplug anything to get a sensible setup. Six settings, spread across three apps, do most of the work.
What each assistant keeps, and for how long
Amazon keeps voice recordings until they are deleted, and offers automatic deletion after 3 or 18 months. Google stores Assistant interactions inside Web & App Activity, where audio can be included or excluded, with auto-delete at 3, 18 or 36 months. Apple ties HomePod requests to a random identifier rather than your Apple Account, and switching off “Improve Siri & Dictation” stops the audio being retained for review — a genuinely different model, and the reason a HomePod has less to configure.
None of that is sinister on its own. The point is that a recording of your kitchen from eight months ago has no value to you and some value to a subpoena, a breach, or an employee reviewing samples.
Set auto-delete rather than deleting once
In the Alexa app, open More → Settings → Alexa Privacy → Review Voice History and choose Auto-delete: 3 months. For Google, go to myactivity.google.com, open Web & App Activity, and set auto-delete to 3 months following Google’s own instructions for deleting Assistant activity. Do the same for YouTube history while you are on that page, since it feeds the same profile.
“Delete all recordings” is a one-off button and it refills by tomorrow. Auto-delete is the setting that keeps working while you forget the page exists.
Know what the mute switch actually cuts
On an Echo, the microphone button on top lights red and disables the wake word entirely; alarms and timers already set will still fire, you simply cannot add a new one by voice. Google’s Nest speakers carry a rear switch that does the same job. The HomePod has no hardware mute at all, so the options are the Siri toggle in the Home app’s speaker settings or pulling the power lead.
Muting is the right move for a call about medical results or a salary negotiation. It is the wrong move as a permanent policy, because you paid for a voice assistant and a muted one is an expensive kitchen clock.
Audit skills and their permissions
Third-party skills are the largest blind spot. Many request your name, address and phone number to “personalise” a quiz or a pizza order, and a surprising number are abandoned projects that still hold access. In the Alexa app, open Skills & Games → Your Skills, sort by recently used, and disable anything you cannot remember enabling; then check Alexa Privacy → Manage Skill Permissions for what is still readable. The same logic applies on your phone, where a fifteen-minute Android permission audit catches apps holding contacts or location they never needed.
Turn off voice purchasing at the same time — Settings → Account Settings → Voice Purchasing — or set it to require a spoken 4-digit code, which stops a television advert from ordering anything. On Google, review Assistant → Your data in Assistant and switch off personalised ads derived from Assistant activity; on Amazon, the equivalent is under Alexa Privacy → Manage Your Alexa Data.
Drop In, and the network underneath
Amazon’s Drop In lets another account open a live audio channel to your speaker without you answering. If you never use it, set Devices → [your Echo] → Communications → Drop In: Off. Google’s equivalent is Nest camera and speaker access shared through Home members, so check the member list in the Home app and remove anyone who no longer lives there.
As a final layer, put speakers on the guest Wi-Fi network instead of the main one, and disable UPnP on the router. A speaker that can reach your laptop can be used as a stepping stone if its account is compromised; a speaker that can only reach the internet is a much smaller problem. If the speaker also controls plugs or bulbs, treat those accounts as part of the same perimeter — the first five smart home devices guide covers which ones need their own login.
If you touch exactly one screen today, make it Alexa Privacy → Review Voice History → Auto-delete: 3 months, then the matching setting at myactivity.google.com. Everything else on this list is a preference. That pair is the difference between a device holding three months of your kitchen and one holding three years.