How Loud Are Drones?

If you live in a quiet neighborhood, then odds are you want to know to know how loud are drones before you commit to a product. Luckily, in this article, we explore why some drones are louder than others, as well as some of the quietest drones on the market right now.

Anyone who owns or knows someone who owns a drone is likely familiar with the loud noises the machines make when they start up. The sound, which often sounds like a tiny, miniaturized lawn mower is instantly recognizable.But exactly how loud are drones? The answer depends on two major things: the type of drone you fly and how high up in the air it is flying. Even loud drones once they reach roughly three hundred feet high cease being noisy for the average listener. At a low height produces a distinctly loud humming sound.It is true that many types of drones are louder than the average car. However, there is a good reason for this phenomenon, which we will explore later in the article. In the meantime, let us talk about what specific circumstances drones are appropriate for sound-wise.Naturally, when we talk about drones on this list we mean the electronic handheld models that anyone can buy and register. Unmanned UAV drones that fly miles above the sky are quite a lot louder than the electric models, but we cannot hear them when they fly because they are too high up.Still, these civilian electronic drones traditionally get a terrible rapt as noisy bits of aircraft that distract people in public space. While it is true that the sound of a loud hum can be quite abrasive to someone who is not used to it, when you compare the sound of a car or motorcycle, it is not that bad.Indeed, the noise pollution from drones is not as big a deal as some people make it out to be. However, you should know why your drone makes the sounds it makes. You should also try and be as courteous as possible to others around you when you fly your crewless aircraft.

Photo by The Lazy Artist Gallery from Pexels

Now that we answered the question "how loud are drones?", Let move on to the question "Why are drones so loud?". This question will help users gain a more specific picture of why the drones make such a high pitch noise.The buzzing noise that we are all familiar with from rotor drones comes from engine forcing the rotor to cut through the air. These rotors slicing through the sound barrier create the distinct buzzing sound that accompanies many drones in flight.When a drone flies the propellers on the device converts the energy from the spinning motor into a downward thrust of air that causes the device to rise, fall and remain at a level in the air. Unfortunately, these drones are not nearly as efficient as we might think they are.A lot of the energy produced by them — around thirty to forty percent — is lost through heat and noise. So, the more efficient a propeller is, the louder it will be. That is why when a drone comes with a propeller that is weaker than the others, then that deficient propeller is louder than the rest.The efficiency of a propeller depends on a variety of factors like the number of blades on the propeller, the shape of the propeller, the revolutions per minute, diameter and pitch. If the drone comes with more leaves, then odds are it will be less efficient. Try and look for propellers with two blades on them.In terms of diameter, you should look for blades that are long and large. These blades require less force to propel the drone up through the air. On the other hand, smaller blades must spin quicker and quicker, which need much more energy. As such a lot of it wastes the energy on revolving them.

The answer to this question comes down to the frequencies of the sounds produced. Car engines produce rumbling low frequencies — deep bass sounds that are harder for many humans to register. Small drones, on the other hand, produce higher vibrations.Think of the sound a bug makes when it flies into your ear. You are picking up the annoying screeching high range of the wings. The same thing happens with some drone models, which is why NASA officially rates them higher in terms of noise pollution than cars.

Photo by Josh Sorenson from Pexels

In terms of noise, generally drones with small rotors create an annoying shrieking sound when they hover at ground level. This shrill sound comes from wasted efficiency and higher levels of revolutions per minute. As such, racing drones are among the loudest models on the market right now.On the other side of the spectrum, larger drones with big propellers in diameter are generally much quieter since they do not waste quite as much energy when in use. These types of drones produce a steady humming noise — not the high pitch screech of the smaller models.

If you live in a quiet neighborhood, then odds are you might be a little embarrassed about getting a particularly loud drone. Nobody wants their neighbors mad at them. Luckily, we included some of the quietest drones currently available on the market right now.

Featured image source: pexels