A Lion's Roar!
Madikwe Game Reserve. Male lions roar to show their territory or to reconnect with pride members. The special shape of their vocal chords (flat and square instead of a triangle common to alot of other mammal species) allows the tissue to respond more easily to passing air, letting these lions roar louder with less lung pressure! When this guy roared you could feel the vibrations in your chest. It is one of the most humbling and moving experiences!
Read more: http://www.smithsonianmag.com/science-nature/secrets-of-a-lions-roar-126395997/#fTwhM2aOP4ALFcpO.99