Research: the hedgehog hears ultrasound, i.e. really high frequencies

Hedgehogs will soon wake up from their hibernation. In the scale of history, it hasn’t been long since the spiked ball rustling in the yard was a strange foreign species that arrived in Finland from the south.

Newspaper Hämäläinen wrote about a hedgehog seen in Hämeenlinna in the summer of 1879:

“These animals have not been seen from Finland other than Uusimaa, where they are sometimes said to have come from the Wiro people’s ships. So this must have marched here from the Helsinki region, and Walla must have been riding the train”.

British Researchers from Oxford and the Danish University of Aarhus have now discovered new facts about the hedgehog.

The hedgehog can hear ultrasounds, even higher frequencies than dogs and cats. In Biology Letters according to a published study, the hedgehog’s hearing reaches up to 85,000 hertz.

The upper register of human hearing ends at 20,000 hertz. Frequencies higher than that are called ultrasound, i.e. supersound, for the very reason that humans cannot hear them. A dog’s ear reaches 45,000 and a cat’s 65,000 hertz.

Researchers borrowed 20 hedgehogs from Danish animal clinics. Sensors were installed on their heads that measure the brain’s electrical reactions to sounds. An accurate model of the structure of the hedgehog’s inner ear was also created on the computer.

It was confirmed that the hearing range of the hedgehog extends from 4,000 hertz to 85,000 hertz. It is not known why the hedgehog can hear such high-pitched sounds. Perhaps detecting high-pitched chirps helps hedgehogs find insects for food?

Hedgehogs a huge number die in traffic every year. The researchers are thinking about whether it would be possible to develop some kind of ultrasonic warning for cars, which would prevent hedgehogs from entering the road.

Older motorists still remember the elk whistle. This miracle invention of the 1980s was said to scare deer off the road. Whistling plastic whistles were tuned to cars, although there is no evidence of their functionality.

Today, however, electric cars have speakers that play an artificial engine sound. They could produce even higher sounds.

Could the new traffic safety invention of the 2020s be… a hedgehog whistle?