Turn off summary announcements in Mac Mail

When an email message arrives on my Mac, I get a chime. I love the chime. The chime is great.

The problem occurs about four seconds later. VoiceOver reads me a summary of the email message. Is there a way to turn this off?

I didn't mind the summaries when Sequoia introduced them. They seemed downright helpful. But lately they've become annoying. They cannot be silenced with the Control key, for starters. And, even if I'm rapidly typing away in another app with keyboard echo set to characters, the Mail summary announcement somehow manages to take priority over several keystrokes. It's very disruptive.

Clearly, I could just close the Mail app. But I rather like the non-intrusive chime when a message arrives, a behavior that we've had for years that has worked fine. I want that functionality back.

Any suggestions for how to disable VoiceOver reading email message summaries? Thanks.