Delivery drones are larger and therefore quieter (larger propellor = more pleasant tone and lower RPM) and fly higher than the consumer drones you’re probably familiar with.
"As you can hear for yourself, this Apache helicopter is nearly unnoticeable next to this handheld drone."
I routinely have Apache helicopters fly over my house and I prefer them to most of the tiny drones. The helicopters typically have lower frequencies and fly way higher. They also don't have that insect flying by your head buzz that makes my ears hurt.
Well, they are, technically…
Are you looking forward to jet-propelled delivery drones?