Both male and female humpback whales vocalize, but only males produce the long, loud, complex "song" for which the species is famous. Each song consists of several sounds in a low register, varying in amplitude and frequency and typically lasting from 10 to 20 minutes. Individuals may sing continuously for more than 24 hours. Cetaceans have no vocal cords, instead, they produce sound via a larynx-like structure found in the throat, the mechanism of which has not been clearly identified. Whales do not have to exhale to produce sound.