Drones have made one of the biggest shifts in today’s industry, and their usage is increasing day by day. Drones can reach places that we would never reach by ourselves. One of the flaws we can say that today’s drones have is their buzzing noise, which can sometimes get on nerves. If drones replace classic way of package delivery in the near future, sound will be one of the factors that should be reduced or eliminated.
So Can Drones Be Silent? Drones create a buzzing noise because of their motors and propellers that create air velocity over the blades. Therefore, drones can’t be completely silent. The only way drones can reduce their noise for several decibels is by adding the appropriate type of „silent propellers“ and propeller shrouds.
Can Drone Noise be Reduced?
Yes, NASA is working on a project that will try to reduce the noise of the drones, and they did so by increasing the small number of propellers to make less noise than a few large propellers. The reason this is possible is that each of these smaller propellers rotates at a different (non-synchronized) speed (RPM), and these sounds do not make one common buzz sound but more of a smaller sounds. NASA has therefore created a GL-10 drone that can fly at 98 feets above the ground and be completely silent.
As for commercial drones that are used on a daily basis, their sound can be reduced by a different choice of propeller design. That „silent“ propellers are better than the classic ones because they are made with a new aerodynamic design, thus reducing the flow of air through the propellers that create vibration and sound.
Why Drones Make Noise?
Drones emit a buzzing sound, which is caused by motors and propellers that produce it during rotation, and thus they create vibrations. Therefore, drones that are larger in size and thus of the aforementioned components will be much louder than smaller ones. Take for example a helicopter that is quite loud because of its large rotating blades and motors that drive him. So nowadays, future drone buyers are starting to consider also the noise factor that drone produces as they fly a short distance away from them. However, we must understand that drones can by no means be silent, but that the only thing we can do is pick a drone that is less noisy than others.
How Loud Are Drones Actually?
The noise the drone produces depends on the drone type and the propeller size. The types of drones most commonly used today by category are professional drones, hobby drones and mini drones. We can say that hobby drones produce noise level around 75 dBA when they fly over our heads, while at longer distances this noise decreases dramatically. The human ear can listen to sounds up to 70 dBA as long as you want, while sounds exceeding 85 dBA can harm the human ear if exposed for more than 8 hours in a piece.
Is It Dangerous To Be Exposed To Buzzing Sound of Drone?
Being exposed to the buzzing sound of a drone for a while is not detrimental to our ears, but exposure to that kind of sound all day can be detrimental. The amount of time a person spends in loud sounds is an important factor. The World Occupational Safety Chamber has clear rules that say that people and workers should not be exposed to sound of 85 dBA or more at a place where they work for 8 hours as hearing damage may occur. The FAA is also subject to similar rules and states that quadcopters must not produce noise greater than 70 dB for a 24h period.
Therefore, before drones come into commercial use at all, such as drone delivery, this problem will need to be addressed. Because if cities are flooded with drones and their buzzing sound is not resolved, it could do more harm than good to use them.
Where Do Quiet Drones Have Advantage?
The role of silent drones somewhere can be very important factor, so some institutions such as the police, the military, animal monitoring situations and filming industry use drones for monitoring. When we talk about the police, they are increasingly using drones as a means of tracking suspects or in crisis situations where they send a drone to survey a hostage situation. Monitoring animals in the wild also has one of the great advantages, because the drones that make noise scare the same animals and thus cannot be monitored. As for the military, they also aim to keep the drones as quiet as possible for espionage and unnoticed shooting. When it comes to filmmaking, drones that make too much noise can spoil the recording with sound, and movie scenes must be recorded and assembled separately, which takes a lot of time and money.
TOP 3 Quietest Drones For Sale
DJI Mavic Pro Platinum
Mavic Pro Platnium have one big exception unlike most DJI models and it’s the quietness of the drone. DJI claims they have reduced the noise by 8 decimal points. Some people will say it does not sound like a lot, but the way the decibels are calculated, that is about the 40% reduced sound than before. The way they achive this is by updating the propeller design and updating the ESCs that are controlling the motors. The Mavic Pro have a new type of battery that should get you around 30 minutes of flight. Few specs that are really important for this drones are the weigh of just 1.62 pounds (732 g), the speed of the drone is up to 40 mph in sport mode without wind and it has a CMOS senesor. This drone also has a high quality camera that can provide high quality images as well as videos with 4k (4096 x 2160) with 24 fps . So if you want a lot of quieter drone then others, my recommendation is DJI Mavic Pro Platinum. You can check the price HERE ON AMAZON*.
Parrot Mambo
This mini quadcopter Parrot Mambo has some cool features that you can see on the drone. Major specs about this drone is that Mambo is super lightweight drone, his flight time is up to 9 min per charge with a battery of 550 mAH. It can reach speeds of up to 18 km/h (11 mph), and it has working radius of approximately 20 meters. In terms of price, this is one of the cheapest drones available on the market. Parrot Mambo does not belong to loud drones, and its use indoors does not interfere with your conversation. Therefore, we can freely state that this is one of the quieter drones on the market. You can check the price of this drone HERE ON AMAZON*.
DJI Spark
DJI Spark is the cheapest and smallest drone that DJI makes, and it’s as good of a drone as you will ever need to get. Its dimensions are 143 x 143 x 55mm, and it weighs approximately 300 grams. The design of Spark is great,and it’s a good looking drone. To control DJI Spark you need to use your mobile phone and plug it into a controller, so you’ll get a live preview from the air. Also, Spark have a feature called „palm launch“, which you can control your drone from your hand. It can stay in the air for about 16 minutes and has a 12MP camera. The quality of this drone is unquestionable, and therefore its design is quite beautiful. This drone is a couple of decibels louder than the previous Parrot Mambo model, but still much better than most commercial drones that make much louder buzz noises. This drone also features LED lights that give better visibility and orientation when flying. You can check the price of this drone HERE ON AMAZON*.
Tips On How To Make Your Drone Quiet
You have purchased a drone, but your family or neighbors are complaining about the noise your drone is making. The first thing you need to know is that a drone will never be able to reduce the noise completely, but what you can do is try to reduce it by a few decibels. The things you can do to keep your drone quieter are:
Select The Appropriate Propeller Design
There are various types of propellers on the market today that know how to drastically reduce the buzz noice that drones produce. Therefore, drone manufacturers began to design the aerodynamic propellers that produce less dB through computer simulations. Some propellers can even reduce the sound up to 50% unlike the classic ones used on most drones. So look online for silent propellers for your drone.
Use Propeller Shrouds to Reduce The Noise
The highest noise from a drone comes from rotating propellers that are creating a wave drag. The way you can reduce noise is by adding special enclosures around the propeller to optimize your drone’s new design. In this case, the noise coming from the propeller is directed upwards, resulting in almost 40% less buzz. Today, companies are specializing in the manufacture of such special enclosures and are working on special materials that have the potential to reduce and attenuate sound, where this efficiency could go up to 60%.
Special thanks to Mario from www.dronetechplanet.com for this guest commentary.
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