Hounds' sounds are the vocalizations that dogs make to communicate with each other and with humans. The most common hounds' sounds are yelps, barks, and grrs. Yelps are high-pitched, short vocalizations that dogs make when they are excited or in pain. Barks are louder and deeper than yelps, and are used to express a range of emotions, from excitement to aggression. Grrs are low-pitched growls that dogs use to express anger or fear.