Giraffes primarily communicate with each other using infrasonic sounds and vibrations, much like dolphins and some whales. Although giraffes are among the tallest mammals on the planet, they are some of the most silent. Giraffes rarely utter vocal sounds, although they occasionally interact with each other via grunts or high-pitched whistle-like cries.
Although rarely heard, giraffes infrequently exchange communications by moaning, snoring, producing flutelike sounds and hissing. As with the noises of other organisms, the sounds produced by giraffes indicate emotions, express fear and anger, and warn other herd members of impending danger. When frightened or startled, for instance, giraffes grunt or snort. In doing so, they warn nearby giraffes of intruders and predators. Mother giraffes may whistle or click to their young calves, which is understood as a sign of encouragement. Mother giraffes may also express grief or panic at the loss of their calves by making loud, repetitive bellowing calls. Lost calves may then return their calls by mewing or bleating. Sometimes, giraffe males produce coughing or hacking sounds to attract females during mating
Although largely silent, giraffes make good use of their height and vision to communicate. They maintain visual contact with each other when traveling, which enables them to warn each other of predators.