I turned on recording indication sounds on my Google home in accessibility options. Now I hear it beep and randomly start listening when my wife and I talk. Sometimes it does it randomly without me making a sound. I ask it what's up and it ignores me and goes to sleep. Smart speakers are so dumb I'm hardly surprised by this.
Based on Amazon's response I assume the device didn't notify the user at all and it wasn't just a matter of not hearing it.