at the beginning on the trail, i turned to my right to listen.
http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Ruffed_Grouse.html#fig1 (listen too).
at the moment, i registered it was a ruffed grouse, my first encounter with one.
and at the time where i listened, twice, it was so distant and in altered frequency that for a few seconds, my heart and the grouses' drumming were connected.
it was as if the drumming was coming from my heart.
(listen to the clip, seriously, you will understand what i mean, and try it with headphones)