The National Fire Protection Association (NFPA) recommends testing your smoke alarm
monthly, but data shows that 90% of Americans don’t do this as often as they should.* So,
the 2nd gen Google Nest Protect has a microphone: it can listen to its horn and speaker tests and
confirm that they’re working. This helps make sure Nest Protect will speak and sound an
alarm when there’s smoke or carbon monoxide.
During Sound Check and Safety Checkup, Nest Protect's microphone is on for a few seconds
— just long enough to make sure the speaker and horn are working. During that time, the
microphone is checking to hear Nest Protect make this sound:
Sound Check runs automatically once a month, at the time of day you choose. If your Nest
Protect has a working Wi-Fi connection, you'll receive an alert on your phone letting you
know when it's about to happen.
Safety Checkup is a manual test that runs only when you tell it to. You can either press the
Nest button on a Protect, or use the Nest app to start the test with a 2nd gen Nest Protect.
The microphone is on only at the end of Safety Checkup, when Nest Protect is checking its
speaker and horn.
How long is the microphone on for?
Nest Protect's microphone is on for a few seconds during Sound Check and Safety Checkup,
in order to record the test sound and compare the recording with the test sound it expects to
The audio from Sound Check and Safety Checkup doesn't leave your Nest Protect and isn't
transmitted to Nest servers.
Can I turn off Sound Check?
Yes. You can turn off Sound Check during the setup process or by going into Settings in the
You can also choose to skip a test any month. Once you've enabled notifications, Nest
Protect can send you a message about five minutes before it runs a test, where you can
choose to skip this month's test. Nest Protect will try again next month.
If you disable Sound Check, but you still want to test the speaker and horn, just run a Safety
Checkup. The microphone in Nest Protect will listen for the speaker and horn every time you
run a Safety Checkup, even if Sound Check is disabled.
We know that your home is a private space, and we've designed Sound Check and Safety
Checkup with that in mind. You can read more about our commitment to user privacy here.