If it's compact enough to compete with 2-strokes, it's likely way quieter than that. In theory a rotary would be quieter than a similarly powerful spoark-ignited engine due to reduced vibrations, but I don't suspect it's a huge difference.
Know what's really quiet? High loitering kamikazi drone and gliding that last while:
> We passionately create technologies of tomorrow because our reality is your future
Not sure this is the strapline I'd choose for my weapons manufacturing company.
Why not?
If the future is autonomous drones killing kids in Pakistan, I don't want to go there.
You can hear it in the video and it is pretty quiet. They've also developed a system where you can shut off the motor and cruise on battery power for short bursts for stealth type applications.
It weighs 1/5th of comparable engines. Some of that saved weight can be put into sound proofing and a muffler.