Braille
Braille is a tactile writing system used by blind or visually impaired people. It can be read either on embossed paper or by using refreshable braille displays that connect to computers and smartphone devices. Braille can be written using a slate and stylus, a braille writer, an electronic braille notetaker or with the use of a computer connected to a braille embosser. For blind readers, braille is an independent writing system, rather than a code of printed orthography.
Braille is named after its creator, Louis Braille, a Frenchman who lost his sight as a result of a childhood accident. In 1824, at the age of fifteen, he developed the braille code based on the French alphabet as an improvement on night writing. He published his system, which subsequently included musical notation, in 1829. The second revision, published in 1837, was the first binary form of writing developed in the modern era.
Braille characters are formed using a combination of six raised dots arranged in a 3 × 2 matrix, called the braille cell. The number and arrangement of these dots distinguishes one character from another. Since the various braille alphabets originated as transcription codes for printed writing, the mappings vary from language to language, and even within one; in English braille there are three levels: uncontracteda letter-by-letter transcription used for basic literacy; contractedan addition of abbreviations and contractions used as a space-saving mechanism; and grade 3 various non-standardized personal stenographies that are less commonly used.
In addition to braille text, it is also possible to create embossed illustrations and graphs, with the lines either solid or made of series of dots, arrows, and bullets that are larger than braille dots. A full braille cell includes six raised dots arranged in two columns, each column having three dots. The dot positions are identified by numbers from one to six. There are 64 possible combinations, including no dots at all for a word space. Dot configurations can be used to represent a letter, digit, punctuation mark, or even a word.
Early braille education is crucial to literacy, education and employment among the blind. Despite the evolution of new technologies, including screen reader software that reads information aloud, braille provides blind people with access to spelling, punctuation and other aspects of written language less accessible through audio alone.
While some have suggested that audio-based technologies will decrease the need for braille, technological advancements such as braille displays have continued to make braille more accessible and available. Braille users highlight that braille remains as essential as print is to the sighted.
History
Braille was based on a tactile code, now known as night writing, developed by Charles Barbier. In Barbier's system, sets of 12 embossed dots were used to encode 36 different sounds. Braille identified three major defects of the code: first, the symbols represented phonetic sounds and not letters of the alphabetthus the code was unable to render the orthography of the words. Second, the 12-dot symbols could not easily fit beneath the pad of the reading finger. This required the reading finger to move in order to perceive the whole symbol, which slowed the reading process. Third, the code did not include symbols for numerals or punctuation. Braille's solution was to use 6-dot cells and to assign a specific pattern to each letter of the alphabet. Braille also developed symbols for representing numerals and punctuation.At first, braille was a one-to-one transliteration of the French alphabet, but soon various abbreviations and even logograms were developed, creating a system much more like shorthand.
Today, there are braille codes for over 133 languages.
In English, some variations in the braille codes have traditionally existed among English-speaking countries. In 1991, work to standardize the braille codes used in the English-speaking world began. Unified English Braille has been adopted in all seven member countries of the International Council on English Braille as well as Nigeria.
Derivation
Braille is derived from the Latin alphabet, albeit indirectly. In Braille's original system, the dot patterns were assigned to letters according to their position within the alphabetic order of the French alphabet of the time, with accented letters and w sorted at the end.Unlike print, which consists of mostly arbitrary symbols, the braille alphabet follows a logical sequence. The first ten letters of the alphabet, a–''j, use the upper four dot positions: . These stand for the ten digits 1''–9 and 0 in an alphabetic numeral system similar to Greek numerals.
Though the dots are assigned in no obvious order, the cells with the fewest dots are assigned to the first three letters, abc = 123, and to the three vowels in this part of the alphabet, aei, whereas the even digits 4, 6, 8, 0 are right angles.
The next ten letters, k–''t, are identical to a''–j respectively, apart from the addition of a dot at position 3 : :
The next ten letters are the same again, but with dots also at both position 3 and position 6. Here w was left out as it was not part of the official French alphabet in Braille's time; the French order of the decade was u v x y z ç é à è ù.
The next ten letters, ending in w, are the same again, except that for this series position 6 is used without a dot at position 3. In French braille these are the letters â ê î ô û ë ï ü œ w. W had been tacked onto the end of 39 letters of the French alphabet to accommodate English.
The a–''j series shifted down by one dot space is used for punctuation. Letters a'' and c, which only use dots in the top row, were shifted two places for the apostrophe and hyphen:.
In addition, there are ten patterns that are based on the first two letters with their dots shifted to the right; these were assigned to non-French letters, or serve non-letter functions: , , , , , .
The first four decades are similar in that the numeric sequence is extended by adding the decade dots, whereas in the fifth decade it is extended by shifting it downward.
Originally there had been nine decades. The fifth through ninth used dashes as well as dots, but they proved to be impractical to distinguish by touch under normal conditions and were soon abandoned. From the beginning, these additional decades could be substituted with what we now know as the number sign applied to the earlier decades, though that only caught on for the digits. The dash occupying the top row of the original sixth decade was simply omitted, producing the modern fifth decade.
Assignment
Historically, there have been three principles in assigning the values of a linear script to Braille: Using Louis Braille's original French letter values; reassigning the braille letters according to the sort order of the print alphabet being transcribed; and reassigning the letters to improve the efficiency of writing in braille.Under international consensus, most braille alphabets follow the French sorting order for the 26 letters of the basic Latin alphabet, and there have been attempts at unifying the letters beyond these 26, though differences remain, for example, in German Braille. This unification avoids the chaos of each nation reordering the braille code to match the sorting order of its print alphabet, as happened in Algerian Braille, where braille codes were numerically reassigned to match the order of the Arabic alphabet and bear little relation to the values used in other countries, and as happened in an early American version of English Braille, where the letters w, x, y, z were reassigned to match English alphabetical order. A convention sometimes seen for letters beyond the basic 26 is to exploit the physical symmetry of braille patterns iconically, for example, by assigning a reversed n to ñ or an inverted s to sh.
A third principle was to assign braille codes according to frequency, with the simplest patterns assigned to the most frequent letters of the alphabet. Such frequency-based alphabets were used in Germany and the United States in the 19th century, but with the invention of the braille typewriter their advantage disappeared, and none are attested in modern use they had the disadvantage that the resulting small number of dots in a text interfered with following the alignment of the letters, and consequently made texts more difficult to read than Braille's more arbitrary letter assignment. Finally, there are braille scripts that do not order the codes numerically at all, such as Japanese Braille and Korean Braille, which are based on more abstract principles of syllable composition.
Texts are sometimes written in a script of eight dots per cell rather than six, enabling them to encode a greater number of symbols. Luxembourgish Braille has adopted eight-dot cells for general use; for example, accented letters take the unaccented versions plus dot 8.
Form
Braille was the first writing system with binary encoding. The system as devised by Braille consists of two parts:- Character encoding that mapped characters of the French alphabet to tuples of six bits.
- The physical representation of those six-bit characters with raised dots in a braille cell.
In addition to simple encoding, many braille alphabets use contractions to reduce the size of braille texts and to increase reading speed.