They even seem to hiccup. During the mating, season various sounds bring males and females together while warning off other males. During the winter, the male is busy establishing his territory. Often in the evening, the male makes a yelling bark, with either short and broken sounds or a single long note. This seems to be a signal to other males to stay away from this territory.
Foxes also have a hair-raising scream that sounds like cats fighting.
The scream seems to be a substitute for fighting. Pups scream at each other during play fighting.