The loudest animal on Earth is the Blue Whale.  The Blue Whale is also an endangered mammal and largest animal that ever lived.  The call of a Blue Whale reaches up to 188 decibels (this is in comparison to human shouting, which reaches up to 70 decibels).  The second loudest animal is the Howler Monkey, which lives in the rain forests of South America.

You can hear a recording of the blue whale call here:

What an amazing creature:

The loudest animal in the world is the blue whale. It creates sound at 188 decibels. To put this in perspective, when a human shouts they create 70 decibels. A jet engine creates 140 decibels

The animal holding the record for producing the loudest sound is the blue whale. Their low-frequency sounds can reach 188 decibels and can be heard at distances of over 500 miles. That's louder than a jet engine 30 m away or a rifle shot 1 m away. The howler monkeys are the loudest on land.