A similar suggestion to the other poster:
Try relocating one of the troublesome units to someplace nearby but not mounted to the ceiling. The top of a bedroom dresser, the floor, a bathroom countertop, the top step of the stairs, halfway down the stairs, hanging from a wall (picture hook)… just get creative.
And since you haven’t mentioned it, I presume these are all smoke detectors? Do you have any heat detectors or carbon monoxide detectors installed?
Very true, and along the lines of what I was thinking.
But it wouldn’t surprise me if there were a way to establish a voice print. In fact, isn’t that already a thing? Even if it is a little rough around the edges, it wouldn’t surprise me if we were even closer to a higher reliability than thought.
With or without that, consider the copyright infringement suits for someone wanting to protect their song, melody, or whatever. Someone could poke at the 8 keys of a toy piano, and if a music artist’s legal team felt it sounded close enough to the original? The ol’ beatdown-by-seeking-damages trick if not a cease and desist order.
Anyway. If someone has enough money and too much time, they’ll make a case out of anything.
“This here’s the Lockpocking Lawyer, and today we’re going to take a closer look at the Flipper Zero….”