The source you link to explicitly says that it does not listen to your microphone without your permission or knowledge: > First and foremost, while we do downl

The source you link to explicitly says that it does not listen to your microphone without your permission or knowledge: > First and foremost, while we do download the hotword module on startup, we do not activate it unless you opt in to hotwording. If you go into "chrome://settings", you will see a checkbox "Enable "Ok Google" to start a voice search". This should be unchecked by default, and if you do not check it, the hotword module will not be started.