Sorry for the late response here, but I wanted to make sure we got this addressed.
Thank you for bringing this up. Google Nest Protect has a built-in microphone that lets it check its own speaker and horn during each automatic monthly Sound Check or manual Safety Checkup test, Nest Protect uses its speaker and horn to make a short sound, and then uses its microphone to listen for that sound. If the microphone hears the exact sound that it expects to hear, Nest Protect will know its speaker and horn are working the way they should, and it shows you that everything is working in the app. Sometimes it can't verify the voice if Nest Protect didn't hear the exact sound it expected. For example, there might have been a loud noise at the same time as the test, like a door slamming or a TV playing with the volume turned up. Once you confirm that there are no unnecessary sounds that can interrupt the test, you can run again a manual Safety Checkup with the Nest app, or by pressing the Nest button twice, and listen for Nest Protect to sound.
I have had this issue on just one of my three. It has been the case since it was installed. For about a three month period six months ago, it showed fine, then reverted to the voice couldn’t be verified.
Thanks, Garrett. I’ve conducted the reset as you suggest several times. (I actually did all that before posting my question as that was the troubleshooting advice.) The problem persists. Do you have any other suggestions that might fix the problem? I see that several other people have this issue and seem to be unable to get it resolved. Thanks in advance.
Sorry to hear you're still having problems with this. Were you able to perform the Sound check as asked previously? If so and it's still having issues, have you tried to factory reset the device as well?
I look forward to hearing from you.
Same problem here, started after a battery replacement: 1 out of 4 nest protects keeps reporting the voice problem and also repeats the message a other nest protect battery is low, although ALL nest protects batteries are renewed.... Strange...
I ended up having to contact Google’s customer service and getting a replacement Nest Protect. Can’t say its “new” as Google said it could replace my brand new, defective Nest with a refurbished one at its sole option. None of the troubleshooting worked for my old Nest. So far the replacement Nest seems to be working fine. Hope this helps. Good luck in getting your issue sorted!