A virtual reality exhibit is giving visitors the extreme ranges of sight and hearing that many animals have.

一套虚拟现实设备可以给人许多动物的极致的视野和听觉。

The view of a bird's nest is different in visible, infrared¹, and ultraviolet

The so-called "immersive" exhibit shows what it might be like to see with birds' ultraviolet（紫外线的） vision or hear with whales' ultra-low frequency hearing.

The researchers say the project aims to demonstrate for the public all the sensing ranges animals experience that are described in scientific literature.

The exhibit is on display at the annual Siggraph conference in New Orleans, US.

The light that humans can see and sounds they can hear are just a small sliver² of the total range of those experienced by animals.

Many creatures can both make and perceive sounds at higher and lower ranges than we can hear - dogs' perception（认识，观念） of ultrasound（超声） is a well-known example.

Several animal species are known to be able to perceive light at extreme ranges; birds can see ultraviolet light and their plumage（翅膀） is often highly reflective in this range.

Predators³ such as rattlesnakes（响尾蛇）, on the other hand, are sensitive to infrared light, seeing the "heat" given off by their prey⁴.

Carol LaFayette of Texas A&M University's visualisation department and her team wanted to make those senses available to the public.

"If you were walking through the woods and you had the ability to see in ultraviolet, for instance, things like birds or fungi⁵（菌类，蘑菇） might stand out in very colourful ways," she told BBC News.

"These species aren't very exotic（异国的，外来的）, they're all over the place.

"There is a wealth of information out there in scientific research that is difficult to access and present. Our project makes these fascinating stories accessible to a wider range of people."

The team consulted a number of researchers, gathering⁶ together a candidate list of species and even some infra- and ultrasound recordings⁷ of animals in the wild.

Deep immersion⁸

The system comprises five large projection⁹ screens designed in a semicircle.

The virtual reality scene is based loosely on Cocos Island, west of Costa Rica, and visitors to the exhibit can wander through the island's forests or swim in its tropical waters, navigating¹⁰ with the aid of a modified Nintendo Wii game controller.

They can switch between ranges of sounds or sights that they might see.

An ultraviolet setting paints a picture rich with both normal colour and reflections we can't normally see. Visualisation expert Fred Parke has designed the system such that it corrects for perspective as users navigate¹¹ the space. The programme allows visitors to hear the infrasound vocalisations of whales or the ultrasound clicks of tiger moths（虎蛾，灯蛾）.

The effect, with the aid of surround-system built into the exhibit, is a sense of total immersion（浸入） in the environment, the researchers said.

The sounds can be simply scaled in terms of frequency to a band that humans can hear; "seeing" in ultraviolet, however is a little more difficult. Colours must be assigned arbitrarily（任意地，武断地） to different wavelengths¹² because we simply can't "translate" what it looks like to animals.

The researchers are working to integrate（整合） infrared vision into the exhibit, and are considering how to tackle sensory¹³ modes that humans don't even have - such as sharks' ability to sense electric fields.

"There are things that we can scale, that we can understand because they are things that we can see or hear - then there are things we don't even know how they can be sensed. That's a really fascinating area," Ms LaFayette said.

The team hopes the idea takes root and imagines the potential for a "live feed" of audio and video from corners of the globe both near and far. Subscriptions¹⁴ to a real-time experience could pay for the purchase of land for wildlife, they said.

"The immersive system ties interest in the environment to knowledge gained through scientific research," Ms LaFayette explained.

"We hope this will generate greater interest in what's out there in one's own back yard."

The Siggraph (Special Interest Group on Graphics¹⁵ and Interactive¹⁶ Techniques) annual conference runs in New Orleans from 3 to 7 August.