That night, as I peered and asked questions and chattered my teeth in the bitter desert wind, all the time I could hear the howling of coyotes. It is a sound that begins with a few sharp barks, rather like the whining splash of a horsewhip in the air, and is followed by a long tremulous, singing quaver. By repute this is the loneliest of all earthly sounds.

(- Donald Culross Peattie, The Road of A Naturalist, 1948)

Coyote sound