Electric motors can run at quite high rpms with lower decibels. Sure not silent but the origin is low enough that at a distance say 25 feet it’s almost silent.
True, but remember what’s quiet to a human may be quite different to what’s quiet to a hedgehog. When reading about these things it’s surprising how often things that we might not consider - like how vibrations travel though the ground - can confuse wildlife in ways that we might not expect when viewed through an anthropomorphic lens.
