The only way to turn off the HomePod is to physically unplug it.
Its design is to be always ready to respond to Hey Siri
To stop playing music simply say: “Hey Siri Stop” and music stops.
Alternatively use your iOS device to pause the music.
HomePod
You can also turn off the "Hey Siri" listening/response if needed.......
It's in the Home App - Homepod settings.
I was watching a video review on the Homepod last night and my own Homepods kept responding to the video voice commands. 😁
Temporarily turning my Homepod response off worked slick....
You can also tap the top to pause. It is perhaps worth noting that the HomePod requires access to the internet to process spoken commands.
tt2
Homepod power off
