Apparition really isn't that hard and no matter how much the Ministry wants to fearmonger that they can track it, they can't track it. Apparition in itself is a non-Euclidean Quantum transportation method. As a result, it's neither that hard when you know this nor is it possible to track. It's non-Euclidean in the sense that you're using magic to create a tunnel between two points that are not connected by space and it's quantum in the fact that for a brief moment, however small, there are two of you at once. People don't know that when Apparating you aren't bending two points in space together and diving through that hole, no, god no, if we were doing spacial bending with magic on that scale Wizards would be gods in the literal sense, able to bend dimensions to your will. when Apparating the proper way you're using magic to tap briefly into quantum mechanics and connect yourself with a version of yourself that is in a different location at the same time unobserved and swap them out. once you understand this trick apparitions become more comfortable and quieter. It's like you were trying to force a pin into a hole 4 sizes too small, you substitute the proper size for brute force and it makes a mess of things. Magic is about visualization. The clearer an image you have the easier it is to bring that image into reality. The Ministry gets one thing right, without the proper science behind instantaneous transportation in mind you have to be very determined to force yourself to utilize quantum physics with nothing but magic and prayers, I'm quite impressed no one has imploded yet. Anyways I'm getting off track, my point is that with the proper knowledge and skill not only is Apparition silent but it's quite comfortable and untraceable too, it feels like taking a step through a door, one moment you're inside and the next you're outside.