How good is a fox's hearing?

The red fox, the most common fox species, can hear a mouse squeaking 330 feet away or a watch ticking 40 yards away. Foxes can locate sounds very accurately and use their hearing to find and catch prey.

Red foxes live primarily on rodents but also eat rabbits, raccoons, opossums, birds, small reptiles, fish, insects, berries, fruits, grasses, sedges, tubers, nuts and carrion. They can locate rodents and other small animals underground by sound and dig them up. If a fox's hearing allows it to locate a small animal above ground, the fox stalks it and pounces from as far as 16 feet away, using its tail to steer while in mid-air.