Ya Know NF ....your post got me to thinking.....
what would it take to have silent leaf blowing and or vacuuming
i started to think of a heavily insulated truck that had several layers
of noise reduction and cone baffles to absorb the noise of a motor.
it could be an electric motor to begin with hooked up to a commercial size vac.
this is out of the box thinking....where innovation is Born....
because noise pollution is a reality as is light pollution
where you can no longer even view the stars....at times