They are some of the most extravagant headgear in the animal kingdom, but a moose's antlers are not just for show. Scientists believe they act as elaborate hearing aids that help males to find calling females.

A study has found that the antlers' sound-gathering qualities boost the hearing of the animals by 19%.

Moose, which are called elk in Europe, are well-known for their impressive hearing. Their ears are more than 60 times larger than those of a human, and their calls can travel nearly two miles.

Scientists had previously suspected the antlers helped with locating mates because males with them were found to be better able to locate females than those without.

George Bubenik, of the University of Guelph, Ontario, and his son Peter, of Cleveland State University in Ohio, decided to test the antler amplifier hypothesis by using a moose skull and a fake ear made by a TV special effects team.

The two scientists put a microphone inside the fake ear, placed between the sweeping Alaskan moose antlers. They measured how well the microphone picked up sounds made by a speaker 32ft (10 metres) away while it was either facing towards the sound, away from it, or sideways on into the bowl of the antlers.

The recorded volume was 21% lower when the ear was facing away from the sound compared with facing towards it. But when the ear was facing sideways the sound was boosted by 19%, suggesting that the antlers funnel and amplify the sound, rather like giant ear trumpets.

"These findings strongly indicate that the palm of moose antlers may serve as an effective parabolic reflector which increases the acoustic pressure of the incoming sound," the pair write in the European Journal of Wildlife Research.

George Bubenik told the natural history website loveearth.com: "Does the phenomenon apply to moose only? So far, there is no evidence any other deer species has this capacity."

He said cetaceans with a forehead structure known as a melon might be able to do the same.

The moose with the largest, most palmated antlers lived in the Alaskan tundra, he said. Here, trees were rare so sound travelled further and the animals could communicate over long distances.