As canines, foxes have an array of noises in their lexicon, including barks and howls. Because foxes are relatively small compared to other canines, their vocalizations tend to be higher-pitched than one might expect from a dog or wolf.
Fox noises had quite the pop cultural moment in 2013 thanks to a viral internet hit focusing on the elusive question of what the fox says. As it turns out, foxes make sounds that can be characterized in ways that are similar to dog vocalizations, with barks and howls. However, fox noises are high-pitched, and foxes' howls can even sound like a human woman's scream.
Fox barks are typically quick, and they may resemble "yipping" sounds or the smaller barks that dogs make. According to Popular Science, fox barks are frequently confused with owl hoots. The fox's howl is high-pitched, loud, and emphatic. It is a screaming noise that can be quite startling.
Though domesticated dogs can be quite mouthy and vocal, foxes have a comparatively smaller array of noises at their disposal, though they do communicate through verbalizations. Some of these noises are intended as communications with other foxes, but some noises serve as warnings for potential predators or competitors in the wild.