Question: Do Quadrocopters have to be so noisy? Answer: The videos you have seen likely had a cam mounted on the quadcopter which therefore measures sound waves much closer to the quadcopter than any human normally would. Many current models are very quiet - as an example, you would not even slightly have to raise your voice to speak to someone next to you with a DJI Phantom a few feet away (and it should always be many feet away when operating!) As a small test, I just used a decibel meter to measure a mini-quad indoors about 7 feet away - in this case, a Syma X1 hovering. It measured about 75 db, which does not seem very loud to my ears. It would be even less if I were using the quadcopter outdoors.
