While we don’t know all the details of Amazon’s long-anticipated Prime Air delivery drones just yet, we can guess at some of the specifics along the way. And if a recent patent application the company filed means anything, the drones may have a few things to say.

Amazon filed a patent for automated aerial vehicle technology that has two parts: first is the use of multiple propellers rotating in different directions to cut down on noise, notes The Register. One propeller goes one direction to provide lift.

“While the second propeller may cause lift of the AAV,” the patent suggests, it “may also be operable to produce sound that cancels noise generated by the first propeller.”

The other part of the patent is also split into two parts, and involves using propellers to communicate with folks on the ground.

First, the propellers can be used to make sounds, the patent says, to do things like warn people to get out of the drone’s way.

“Suppose, for instance, that the AAV were delivering an inventory item to a location,” the patent says. “Upon approaching the location, the AAV determines (e.g., based on a video signal fed as an input parameter to the controller via a camera) that a person is situated at or near an intended or a suitable landing area corresponding to the delivery location.”

That information might trigger the drone to utter something like “Watch out!” or other warning messages. The controller can also determine if such a warning is needed, and change up the speed of the propeller to produce “a series of sounds that are audibly perceptible as ‘Watch out!’ ”

Another method would have the drones figuring out whether they need to alert humans that they’re around. In some situations, “light sources [e.g., light-emitting diodes (LEDs)] coupled to one or multiple propellers may be caused to intermittently emit light in a synchronized manner while the propellers are rotating to generate patterns that are visibly perceptible as ‘HELLO’.”

Oh, hey there, drone.

Amazon plans drones with talking propellors [The Register]

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