Literacy within the deaf community, says Laura Blackburn, of the University of Arizona, Tucson, is at "crisis level". By the time they are 18, deaf and hearing impaired people -- who make up 1% of the population -- have an average reading age of only eight or nine years old. In Arizona, a coalition of teachers and researchers have developed a new sign alphabet that they hope will end this educational disenfranchisement.

Deaf children have literacy problems because reading is usually taught by relating words to sounds -- for example, by turning the word 'cat' into three syllables for each of its letters. But natural sign languages such as American Sign Language (ASL), which develop over many years within the communities that use them, not only have quite different rules of syntax and grammar, but clearly cannot be broken down into audible building blocks.

The Tucson team have come up with a new way to bridge ASL and written English. At an elementary school in Tucson, they are teaching deaf children an alphabet of their own, giving them the kind of door to written English that the phonetic alphabet gives to hearing children.

The sign alphabet breaks ASL into its 32 basic components, called 'ASL graphemes'. The team has also developed a script to communicate the graphemes in print.

At the annual meeting of the American Association of the Advancement of Science in San Francisco, Samuel Supalla, also at the University of Arizona, highlighted the obstacles that deaf children face. He discussed how a previous attempt to address the literacy problem -- a US sign language known as Manually Coded English (MCE) --makes children's lives harder by breaking the rules of natural sign languages.

MCE is intended to closely reflect the structures of spoken English by modifying root signs from ASL with new signs to communicate in a more sequential fashion. But in doing this, it seems to become too complex to grasp easily.

In natural sign languages, no one word involves more than two locations, movements or shapes of the hand -- the three carriers of sign information. The shapes must also be related -- you can go from open palm to closed fist, but not from open palm to pointing finger.

But in MCE the sign for 'knowing', for example, involves the sign for 'know', an open palm touched to the forehead, followed by the MCE suffix for '-ing', sweeping the hand away from the body with a raised little finger.

The change in hand shape causes children see the '-ing' as an independent unit, rather than as part of one sign. It therefore tends to break free and roam around the sentence: children sign things such as "Santa Claus is come to town-ing". Other MCE signs, such as 'suspecting', break the rules by containing three components.

The kindergarten test of the new ASL graphemes has only just begun, so it is too early to say whether this approach will be a success. If it is, Supulla hopes that it will be adapted for other sign languages, building a bridge between speech and signing, rather than distorting one to fit the demands of the other. "All I'm asking is that we find a common ground," he says -- or, rather, signs.