The roar of a lion can reach 114 decibels at a distance of 1 metre, and can be heard from 8 kilometres (5 miles) away. As a source of comparison, the sound in the Velodrome at the London 2012 Olympics reached the same levels and was clocked at 114 decibels. A lion’s roar is used as a means of communication, for example to announce their availability to a mate or warn of predators. Roars usually lasts about 30 – 60 seconds.
Scientists have discovered that lung capacity isn’t the reason behind the ability to emit such a loud sound, but actually an unusual set of vocal cords. While hardly using the respiratory system, these vocal cords contain two membranes covered in a layer of fat that allow the cords to vibrate horizontally, producing and magnifying a sound that is both hard and heavy at the same time.