If you think some people are too noisy then wait till you read about some of the loudest animals in the world. A normal human shout is around 70 decibels. Anything above 120 decibels and it becomes physically painful. There are many animals, birds and even insects that can make much louder sounds than that. Sometimes animals use these sounds as mating songs while at other times they use them to scare away rivals. Whatever be the reason, when it comes to making a racket, these animals top the list.