Roar (utterance)

A roar is a type of animal vocalization consisting of both a low fundamental frequency (pitch) and low formant frequency.Mammals of various species have evolved to produce roars and roar-like vocalizations for long-distance communication and territorial or mate defense. These include the big cats, red deer, various bovids, some pinnipeds, bears, howler monkeys, hammer-headed bats,elephants and gorillas.

The ability to roar has an anatomical basis, often involving modifications to the larynx and hyoid bone and enlarged internal air spaces for low-frequency acoustic resonance. While roaring, animals may stretch out their necks and elevate their heads to increase the space for resonance. Though usually airborne, some roars are emitted underwater, as in the case of the male harbor seal.

Roaring mammals have evolved various means to achieve their vocalizations. A proportionally large larynx contributes to a deeper fundamental frequency. The male hammer-headed bat has a larynx that takes up most of his thoracic cavity and is half the size of his backbone. A larger larynx also has enlarged vocal cords which also contributes to a deeper pitch; as the folds increase in mass, their oscillation rate decreases. In addition, the big cats (lion, tiger, leopard and jaguar, referred to as the "roaring cats"), have vocal cords that are square-shaped as opposed the triangle-shaped cords of other felids; this allows them to produce a louder call with less lung pressure. The elasticity of the larynx and the length of the vocal tract affect the formant of a sound. In big cats and male red deer and fallow deer, specialized musculature pulls the larynx deeper in the vocal tract when roaring, lowering the vocal tract resonance.

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