Many animals as well as the person, use sounds for communication. And, if the person for this purpose uses words, animals can transfer information, changing tonality and loudness of the made sounds. The sound is louder, the more tribespeople can hear the transferred message.
Marine animals
Sounds which are made by marine mammals for example whales or cachalots, it is possible to hear, thanks to the fact that they extend low-frequency impulses in the dense environment – water, to hundreds of kilometers. The truth and initial loudness of these sounds is rather big. So, the blue whale makes sounds with a force up to 188 DB, and an adult cachalot – to 116 DB, thus that cubs of a cachalot call mother shouts by intensity up to 162 DB.
Scientists learned to distinguish on the loudness of sounds which are made by these giants, not only their sizes, but also what clan the animal treats. It is also possible to determine by these sounds, than at present it is occupied – hunting, feeding, courting, education of cubs or just communication with each other.
Overland animals
From the animals living on the land the crocodile is considered the most loud. During the marriage period the males can make sounds with a volume of 108-110 DB. However, near it also the hippopotamus left – the loudness of the sounds made by these animals can reach 106 DB.
The donkey roar on loudness is equal 78 DB, in category of pets he is considered a champion.
In the jungle of Central and South America there live monkeys howler monkeys. As follows from their name to shout they masters too. Males under language have a bone bubble in which the made sounds under certain conditions begin to resound, repeatedly amplifying. Shout of males, of course, is not really harmonious – reminds at the same time a roar of a donkey and bark of a dog, but it is possible to hear it for many kilometers.
From birds the Indian peacock possesses the loudest voice. Its sharp guttural shouts are heard for several kilometers.
The "loudest" insects
Despite the modest sizes, some insects can argue with animals on the loudness of the made sounds. So, the ordinary water bug of subspecies of Micronecta scholtzi can chirr with loudness to 105 DB though its sizes and weight million times smaller, than at the same cachalot or a crocodile. Special loudness also males of cicadas who use for their generation vibration of ridge plates in two resonator cavities on a paunch can make sounds. Females can hear these sounds, being at distance several kilometers, and the human ear distinguishes them from several hundred meters. Such insect as a medvedka which lives, having deeply earthed, and eats roots of plants, as required also does not miss an opportunity to get out on a surface and to make a sound which loudness can reach 92 DB the truth a chirr of a medvedka it is possible to hear very seldom.