杏吧原创

There is an uncanny similarity between wolf howls and emergency sirens. The sound of a siren might be effective because we evolved to be alerted by howls, suggest researchers.

Hynek Burda at the Czech University of Life Sciences and his colleagues compared several dozen recordings of wolf howls with the sounds made by various emergency sirens, such as those on ambulances and in tornado-warning systems. Their analysis looked at the most important acoustic components of these sounds 鈥� for example their initial and closing frequencies or how the sounds change from beginning to end.

They found that most of the tested siren sounds 鈥渨idely overlap鈥� with the sounds of the wolf howls, which they call a 鈥渟triking similarity鈥�.

The siren developers almost certainly didn鈥檛 deliberately model their sounds on wolf howls, says Burda. 鈥淏ut if they had looked for sound parameters that effectively propagate and effectively alert humans, then they may have found the same parameters as those of wolf howling.鈥�

Burda and his team suggest that wolf evolution has selected for the sound of the howls as the most effective way of communicating over long distances. These howls, in turn, may have formed a selection pressure for alertness to these sounds during the evolution of modern humans.

Under this scenario, today鈥檚 sirens take advantage of our innate tendency to take note of these aposematic, or warning, sounds, as well as the fact that certain acoustic properties are ideally suited to effectively transmit sound over long distances.

鈥淪irens also effectively provoke wolves and dogs to howl, indicating that the animals themselves consider them to be similar,鈥� says聽Burda.

Burda and his colleagues hope their work will inspire other researchers to investigate how naturally occurring aposematic sounds, such as wolf howls, the buzzing of hornets or the hissing of snakes, can be used to design new warning-sound systems.