Which voice assistant did you have installed?  If Alexa (and I think Google) did you check the corresponding app for activity?

Sonos only 

That is weird. I would do a diagnostic and get that to Sonos.

Any chance that the “Yes” came form a neighbor or something like that?  Perhaps the Move was in bluetooth mode and was playing audio from your phone?

If SVC believes it heard the wake phrase, but no request, it will respond with “Yes?” after 2-3secs.

Therefore it could have picked something up prior to your remark.

It would have been Giancarlo’s voice.

The volume of the assistant corresponds with the volume set on the device, so the volume was set high on the Move for the response to be loud.

My one and only Google Nest Mini - (soon to be given away to family members) - often likes to respond to false wake words ..and makes all kind of comments. I wouldn’t worry to much about such things.

I only have to mention ‘A letter has just come for you’ (or similar comment) and Alexa comes out to play. Just modern day problems, yet to be resolved, I guess.‍♂️

I don’t use GA, but Alexa is definitely the worst for false wakenings. Anytime, the football is on and Alex Oxlade-Chamberlain is mentioned by the commentators…. chime, chime chime…

Echo near but checked log nothing from that time frame 

Your initial description of the incident sounds like what @Mr. T mentions in his first post above. It’s what Mr. Fring will sometimes respond with, if the mic falsely picked up the ‘wake words’ with no follow up.

I posted exactly what was said in a quiet room

My echo wake word is “echo” 

My sonos wake word is hey sonos 

Nothing in that sentence is close to either and the voice coming out of the speaker was nothing like any assistant I have setup 

Say ‘hey sonos’ to the speaker and then just wait a while - you might need to perhaps try it a couple of times, but wait to see if Gus says ‘YES’… then see if that is what you heard.

One false wakening and you remove all voice assistants and disable microphones… slight over reaction.

100% it was Giancarlo.

Ah yes @skullc - you’ll (obviously) need to reinstall SVC on the speaker to test @Mr. T’s theory - but I think Gus was the voice you heard too, and it was just a false wakening.

Just try the SVC wake word (followed by silence) a couple of times, as mentioned in my last post and I think you will hear him say ‘YES’ - as you described in your opening post.

Its not anywhere near as bad as my old speaker - which you can perhaps see liked to keep me awake at night:

ha ha