The idea of a talking, tactile picture - you touch it, perceive the shape with your fingers, and it announces what it is ("dog", "apple") - has been around for some time, and you don't need to be a technological wizard to see that it's relatively easy to achieve.
However, moving forward from that into a multi-layered, multi-sensory tool that offers real educational value across a wide range of ages and abilities is a challenge of a different order. But it has been met by the Royal National College for the Blind (working with Anglia Polytechnic University) with its T3 (talking tactile technologies) system.
HOW T3 WORKS
Developed for Europe from a US product originally devised by Touch Graphics of New York, the hardware side of T3 is a touch screen in a plastic holder, typically resting on the desk and connected to a computer. Tactile overlays are then placed on the screen.
For example, if you mount a tactile map of the world on the screen and touch Australia, you'll hear the word "Australia". Already this is useful.
However, touch Australia a second time and you'll hear the word spelt.
Touch it again and again and you enter an escalating hierarchy of information about the country and its people. The map also has a navigation feature, so you can find another country ("Go east," "Go south.").
These features make it possible for users to find the level and type of information they need. "You can take a diagram of the human heart from early years to university level. The heart doesn't change, but the script does," says Chris Stevenson, business development manager at the college.
A range of overlays, for various curriculum and age levels, is available in the fast expanding T3 catalogue: there are 44 maps, for example, as well as diagrams of everything from the human digestive system to the rainfall cycle. The aim is to provide as full a resource as possible for the national curriculum and other exam and study syllabuses for schools and colleges. There's also an authoring tool, so teachers can prepare their own overlays, using standard devices for producing tactile diagrams. The feeling at the college, though, is that most teachers will want a good choice of off-the-peg overlays.
As well as having raised and textured surfaces, the overlays also have the visual detail and colour necessary for sighted users, underlining T3's multi-sensory aspects. Lesley Wells, the college's researcher who has done much of the development, describes how working with sighted children on an overlay of a growing plant added a new dimension to their learning.
"When you press your finger on the roots you get a sound of sucking water.
When we turned the sound off, children didn't do so well on questions about the function of the roots. T3 is a good medium for a multi-sensory approach to teaching. For a sighted child it is see it, hear it, feel it."
RESEARCH AND DEVELOPMENT
The task of converting pictures and diagrams originally drawn with sighted people in mind into tactile form calls for a great deal of experience and research. Much of this is carried out at Anglia Polytechnic University.
"They've used our students to test thousands of tactile images," says Wells. "They know things like how high a raised line can go, what is the widest circle that can be perceived, or the smallest triangle."
People vary in their ability to feel textures and surfaces, she says. "It's acute in some people. Some can detect by touch when there's ordinary print on a page. But we have to go for the common denominator."
There's much else to consider, too: for example, the best balance between sound effects and speech, and how far to overlap the two. All this must be decided before the author starts to look at curriculum requirements.
For visually impaired or totally blind people, T3 is an immense step forward. They can work at their own pace, repeating where necessary, and calling up information at the appropriate level. Maria Kovacs, who is registered blind and works in the Braille transcription department at the college, says T3 would have made a great difference to her education.
"I was well taught," she says, "but in geography I had to use a hard textured map with Braille labels and a key and somebody had to describe it to me. The T3 does all that at once.
"Making sense of the vascular system - capillaries, arteries and the heart - was difficult. With the T3 I'd have picked things up much more quickly."
Chris Stevenson talks of T3 helping visually impaired learners to take public exams, and to have access to online courses. "It's a whole new world of learning. We've devised it for one group, but it's not just for them."
He expects teachers to find imaginative applications no one has yet considered.
Founded 130 years ago, the Royal National College for the Blind has 200 students on a wide range of courses and carries out research in the field of visual impairment. "Over the years we've learned to develop ways of teaching and training people that are unique," says Stevenson.
The college is at the cutting edge of research and practice in areas where its students can excel. Music technology, for example, is a great strength, and the college has seven professional recording studios.
It is also increasingly providing services and expertise to business and industry. "The residential students love delivered pizzas," says Stevenson.
"But the local pizza place commented that they didn't vary their orders much. So we provided a Braille menu. It's one of those basic accessibility issues."
Stevenson believes this kind of low-tech enterprise is as much an indicator of the college's flexible and responsive approach as is the T3. Another example he shows is a large white plastic hoop in an elongated pear shape, with a handle at the narrow end. This, he says, has enriched the lives of many people with visual impairments. "It's taken people up Ben Nevis and Snowdon."
The Hoople is a development of the familiar white cane; because it has width as well as length, it is better at picking up obstacles off the centre line. "It is difficult to use a cane on rough ground," says Stevenson. "This is the ultimate low-tech mobility device. And it is as innovative as anything else we've done."