This sound is not aurally heard but psychologically heard. It is triggered by viewing a particular scene or image. If you are able imagine and position yourself in different directions of the sound source you will get a different timbral effect. When close the sound is heavy and strong, when afar it sounds much more lighter and rots much quicker. Everyone perceives this sound differently depending on their background but what is most interesting is you can manipulate the sound and change the whole context of the scene or image. In the end, this sound isn't real, it is only a fabrication of what we believe it should sound like.