The engine sound is quite, no increases nor in vibrations. Although both of them seems to slowly increase in intensity as last september before the series of quakes although not so clear and vivid. Perhaps it will after all be a quite year compared to the most active recent ones.
(know your grounds, know your crack, know your tectonic plates.) All in nature is one. If one part is effected so will be the other part and so on and so forth.
(The wolf (sound) is always there and needs not to be mentioned anymore.)