Pant-hoot

The pant-hoot is a loud, structurally complex vocalization of chimpanzees. The call is generally divided into four distinct, successive phases: introduction, build-up, climax and let-down. This introductory phase begins with soft, breathy, low-frequency 'hoo's' that transition into the build-up phase; a series of increasingly rapid, low-frequency in-and-out pants. Following the build-up phase, the call quickly builds into the climax, consisting of loud, high-frequency screams that eventually slow into the let-down phase, similar in structure to the build-up, but with decreasing amplitude and pace until the call is complete.

Both male and female chimpanzees produce these unique vocalizations, with high-ranking adult males predominantly and more frequently emitting the pant-hoot. The pant-hoot is most often produced jointly with other males, in a complementary behaviour known as chorusing, as opposed to producing the calls individually.