I stopped using the word "Alexa" back in Dec on my DOT. My wake word is "Echo."
Echo can pipe up when unexpected too! It's done it quite a bit lately. Our master bathroom (en-suite) Dot is just 20+ feet from the master bedroom Dot. I could use the bedroom Dot from the bathroom but there is the issue of having to turn it up and talk radio playing in the bathroom, water running, etc plus my back to the bedrm Dot so it just made sense to get one for the bathrm. They would both pipe up when I said Alexa so I changed one to Echo. Now with a GH, I'm doing the "Alexa, uh Echo, no Hey Google" thing