Air is expelled through the open mouth while the mouth is progressively closed. People can hear the roaring sound of tigers 3 kilometers away. It is therefore a long range sound telling other tigers of the caller's presence, but also used in other contexts.
A tiger might roar:
- after killing large prey
- before mating
- during mating
- when a female is calling her cubs
Note: (1) Wild Cats of the World ISBN-13: 978-0-226-77999-7