Setting HomeKit scene without Siri voice feedback

Question

I have several scenes set up in HomeKit and I control them by talking to Siri on the Homepod. Most of the time when I set a scene using Siri, she responds audibly with Done or All set. I want to silence the voice feedback. There is one scene in particular, called Bedtime, that works silently, but I can't figure out how to make the other scenes work this way.

At first I thought it was based on the scene name, so I tried renaming Bedtime to Good Morning and I changed the icon too. But it still works silently.

There must be something different about this one scene, the only one which works silently. Is it some hidden characteristic which could be set with a 3rd party app?