World Library  
Flag as Inappropriate
Email this Article

Braille cell

Article Id: WHEBN0004921492
Reproduction Date:

Title: Braille cell  
Author: World Heritage Encyclopedia
Language: English
Subject: Night writing, Braille music, Nemeth Braille, Unified English Braille
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Braille cell

This article is about the writing system used by the blind and the visually impaired. For other uses, see Braille (disambiguation).
Braille
Type Alphabet (non-linear)
Languages Several
Creator Louis Braille
Time period 1824 to the present
Parent systems
Night writing
  • Early braille
    • Braille
Child systems French Braille
English Braille
Bharati Braille
Chinese Braille
Japanese Braille
Korean Braille
etc.
Sister systems New York Point
ISO 15924 ,
Direction
Unicode alias
Unicode range U+2800 to U+28FF

Braille /ˈbrl/ is a tactile writing system used by the blind and the visually impaired. It is traditionally written with embossed paper. Braille-users can read computer screens and other electronic supports thanks to refreshable braille displays. They can write braille with the original slate and stylus or type it on a braille writer, such as a portable braille note-taker, or on a computer that prints with a braille embosser.

Braille is named after its creator, Frenchman Louis Braille, who went blind following a childhood accident. In 1824, at the age of 15, Braille developed his code for the French alphabet as an improvement on night writing. He published his system, which subsequently included musical notation, in 1829.[1] The second revision, published in 1837, was the first digital (binary) form of writing.

Braille characters are small rectangular blocks called cells that contain tiny palpable bumps called raised dots. The number and arrangement of these dots distinguish one character from another. Since the various braille alphabets originated as transcription codes of printed writing systems, the mappings (sets of character designations) vary from language to language. Furthermore, in English Braille there are three levels of encoding: Grade 1, a letter-by-letter transcription used for basic literacy; Grade 2, an addition of abbreviations and contractions; and Grade 3, various non-standardized personal shorthands.

In the face of screen-reader software, braille usage has declined. However, braille education remains important for developing reading skills among blind and visually impaired children, and braille literacy correlates with higher employment rates.

History

Braille was based on a tactile military code called night writing, developed by Charles Barbier in response to Napoleon's demand for a means for soldiers to communicate silently at night and without light. In Barbier's system, sets of 12 embossed dots encoded 36 different sounds. It proved to be too difficult for soldiers to recognize by touch, and was rejected by the military. In 1821 Barbier visited the Royal Institute for the Blind in Paris, where he met Louis Braille. Braille identified two major defects of the code: first, by representing only sounds, the code was unable to render the orthography of the words; second, the human finger could not encompass the whole 12-dot symbol without moving, and so could not move rapidly from one symbol to another. Braille's solution was to use 6-dot cells and to assign a specific pattern to each letter of the alphabet.[2] At first, braille was a one-to-one transliteration of French orthography, but soon various abbreviations, contractions, and even logograms were developed, creating a system much more like shorthand.[3] The expanded English system, called Grade 2 Braille, was complete by 1905. For the blind today, braille is an independent writing system rather than a code of printed orthography.[4]

Derivation

Braille is derived from the Latin alphabet, albeit indirectly. In Braille's original system, the points were assigned according to the position of the letter within the alphabetic order of the French alphabet, with diacritic letters and w sorted at the end.[5]

The first ten letters of the alphabet, a–j, use the upper four dot positions, 1, 2, 4, 5: (black dots in the table below). These stand for the ten numerals 1–9+0 in a system parallel to Hebrew gematria and Greek isopsephy. (Though the dots are assigned in no obvious order, the first three letters and lowest numerals, abc~ 123 , and the vowels, aei , have the fewest dots, whereas the even numerals 4680 are corners, .) The next ten letters, k–t, are identical to a–j, respectively, apart from the addition of a dot at position 3: (red dots below):

Derivation of the 26 letters of the alphabet from the 10 numeric digits
a/1 b/2 c/3 d/4 e/5 f/6 g/7 h/8 i/9 j/0
k l m n o p q r s t
u v x y z w

The next ten letters (the next "decade") are the same again, but with dots at both 3 and 6 (green dots). Here w was left out as not being part of the basic French alphabet; the order is u v x y z ç é à è ù .[6] The next ten, ending in w, are the same again, except that for this series position 6 (purple dot) is used without position 3. These are â ê î ô û ë ï ü ö w .[7] The a–j series lowered in dot space become punctuation; in English Braille these are: comma, semicolon, colon, period, (not used), exclamation point, parentheses, question mark/open quotation, (not used), close quotation: . A and c, which only use the top row, were lowered two spaces for the apostrophe and hyphen: . (Along with the space, these are the zero characters of the first through third decade, at left in the table below.) In addition, patterns based on the first decade shifted to the right were assigned to non-French letters (ì ä ò ) or serve non-letter functions: (superscript; in English the accent mark), (currency prefix), (capital, in English the decimal point), (number sign), (emphasis mark), (symbol prefix).

The 64 braille cells
decade    numeric sequence    shift right
1st
2nd
3rd
4th
5th shift
down

Originally there had been nine decades. The fifth through ninth used dashes as well as dots, but proved to be impractical and were soon abandoned. These could be substituted with what we now know as the number sign, though that only caught on for the digits (1st decade → 5th decade). The dash of the sixth decade was simply dropped, producing the modern fifth decade. See 1829 braille.

Historically, there have been three ways of applying braille to a linear script. Under international agreement, most braille alphabets follow the original French sorting order for the 26 letters of the basic Latin alphabet, and there have been attempts at uniformity for letters beyond these 26 (see international braille), though divergences remain, as in German Braille and the ligatures of English Braille. The agreement was made to avoid 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. (Compare modern Arabic Braille, which uses the French sorting order.) A third application was to assign braille codes according to frequency, with the simplest patterns (and therefore quickest ones to write) 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 (see American Braille), but none are attested in modern use. A convention for the extended letters seen in some alphabets 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. (See Hungarian Braille and Bharati Braille, which do this to some extent.) Finally, there are braille scripts which don't order the codes numerically at all, such as Japanese Braille and Korean Braille, which are based on more abstract principles of syllable composition.

Academic texts are sometimes written in a script of eight dots per cell rather than six, enabling them encode a greater number of symbols. (See Gardner–Salinas braille codes.) Luxembourgish Braille has adopted eight-dot cells for general use; for example, it adds a dot below each letter to derive its capital variant.

Form

Braille can be seen as the world's first binary encoding scheme for representing the characters of a writing system.[3] The system as devised by Braille consists of two parts:[4]

  1. A character encoding for mapping characters of the French alphabet to tuples of six bits or dots.
  2. A way of physically representing six-bit characters as raised dots in a braille cell.[8]

Within an individual cell, the possible dot positions are organized into two columns of three positions each. A raised dot can appear in any of the six positions to form sixty-four (26) possible subsets, including the arrangement in which there are no raised dots. For reference purposes, a particular arrangement may be described by naming the positions where dots are raised, the positions being universally numbered 1 to 3, from top to bottom, on the left, and 4 to 6, from top to bottom, on the right. For example, dots 1-3-4 () would describe a cell with three dots raised, at the top and bottom in the left column and on top of the right column, i.e., the letter m. The lines of horizontal braille text are separated by a space, much like visible printed text, so that the dots of one line can be differentiated from the braille text above and below. Punctuation is represented by its own unique set of characters.Today different braille codes (or code pages) are used to map character sets of different languages to the six bit cells. Different braille codes are also used for different uses like mathematics and music. However, because the six-dot braille cell only offers 64 patterns (26, including the space), many braille characters have different meanings based on their context. That is, character mapping is not one-to-one.

In addition to simple encoding, modern braille transcription uses contractions to increase reading speed. (See: Contracted braille)

Writing braille

Braille may be produced by hand using a slate and stylus in which each dot is created from the back of the page, writing in mirror image, or it may be produced on a braille typewriter or Perkins Brailler. Because braille letters cannot be effectively erased and written over if an error is made, an error is overwritten with all six dots (). Interpoint refers to braille printing that is offset, so that the paper can be embossed on both sides, with the dots on one side appearing between the divots that form the dots on the other (see the photo in the box at the top of this article for an example).

Braille may also be produced using a computer with braille translation software and a braille embosser or a refreshable braille display.

Braille has been extended to an 8-dot code, particularly for use with braille embossers and refreshable braille displays. In 8-dot braille the additional dots are added at the bottom of the cell, giving a matrix 4 dots high by 2 dots wide. The additional dots are given the numbers 7 (for the lower-left dot) and 8 (for the lower-right dot). Eight-dot braille has the advantages that the case of an individual letter is directly coded in the cell containing the letter and that all the printable ASCII characters can be represented in a single cell. All 256 (28) possible combinations of 8 dots are encoded by the Unicode standard. Braille with six dots is frequently stored as Braille ASCII.

Letters

The first 25 braille letters, up through the first half of the 3rd decade, transcribe a–z (skipping w). In English Braille, the rest of that decade is rounded out with the ligatures and, for, of, the, and with. Omitting dot 3 from these forms the 4th decade, the ligatures ch, gh, sh, th, wh, ed, er, ou, ow and the letter w.

ch sh th

(See English Braille.)

Formatting

Various formatting marks modify the letters that follow them. They have no direct equivalent in print. The most important in English Braille are:

Capital
follows
Number
follows

That is, is read as capital 'A', and as the digit '1'.

Punctuation

Basic punctuation marks in English Braille include:

Comma Semicolon Apostrophe Colon Hyphen Decimal point
Full stop
(Period)
Exclamation
point
Open quote,
question mark
Close
quote
Bracket
(Parentheses)
Slash
(Fraction)

is both the question mark and the opening quotation mark. Its placement before or after a word determines its reading.

is used for both opening and closing parentheses. Its placement relative to spaces and other characters determines its interpretation.

Punctuation varies from language to language. For example, French Braille uses for its question mark and swaps the quotation marks and parentheses (to and ); it uses the period () for the decimal point, as in print, and the decimal point () to mark capitalization.

Contractions

For a full list of abbreviations and contractions in English, see English Braille.

Braille contractions are words and affixes that are shortened so that they take up fewer cells. In English Braille, for example, the word afternoon is written with just three letters, , much like stenoscript. There are also several abbreviation marks that create what are effectively logograms.[4] The most common of these is dot 5, which combines with the first letter of words. With the letter m, the resulting word is mother. There are also ligatures ("contracted" letters), which are single letters in braille but correspond to more than one letter in print. The letter and, for example, is used to write words with the sequence a-n-d in them, such as hand.

afternoon
(a-f-n)
mother
(dot 5-m)
hand
(h-and)

Unicode rendering table

Main article: Braille Patterns (Unicode)

The Unicode standard encodes 8-dot braille glyphs according to their binary appearance, rather than following their assigned numeric order. Unicode defines the "braille Patterns" character block in the hex codepoint range from 2800 to 28FF. Dot 1 corresponds to the least significant bit of the low byte of the Unicode scalar value, and dot 8 to the high bit of that byte.

Most braille embossers and refreshable braille displays do not yet support the Unicode rendering table; instead they use braille ASCII for 6-dot braille. Some embossers have proprietary control codes for 8-dot braille or for full graphics mode (where dots may be placed anywhere on the page without leaving any space between braille cells, hence continuous lines can be drawn in diagrams) but these are rarely used and are not standard.

Page dimensions

Most braille embossers support between 34 and 37 cells per line, and between 25 and 28 lines per page.

A manually operated Perkins braille typewriter supports a maximum of 42 cells per line (its margins are adjustable), and typical paper allows 25 lines per page.

A large interlining Stainsby has 36 cells per line and 18 lines per page.

An A4-sized Marburg braille frame, which allows interpoint braille (dots on both sides of the page, positioned out of phase so they do not interfere with each other) has 30 cells per line and 27 lines per page.

Literacy

Main article: Braille literacy

A sighted child who is reading at a basic level should be able to understand common words and answer simple questions about the information presented.[9] The child should also have enough fluency to get through the material in a timely manner. Over the course of a child's education, these foundations are built upon in order to teach higher levels of math, science, and comprehension skills.[9] Children who are blind not only have the educational disadvantage of not being able to see, but they also miss out on the very fundamental parts of early and advanced education if not provided with the necessary tools.

U.S. braille literacy statistics

In 1960, 50% of legally blind, school-age children were able to read braille in the U.S.[10][11] According to the 2011 Annual Report from the American Printing House for the Blind, there are approximately 58,939 legally blind children in the U.S aged 0-21. Of these, about 9% prefer braille as their primary reading medium; 27% are visual readers, 8% are auditory readers, 21% are pre-readers, and 34% are non-readers.[12]

There are numerous causes for the decline in braille usage, including school budget constraints, technology advancement, and different philosophical views over how blind children should be educated.[13]

A key turning point for braille literacy was the passage of the Rehabilitation Act of 1973, an act of Congress that moved thousands of children from specialized schools for the blind into mainstream public schools.[11] Because only a small percentage of public schools could afford to train and hire braille-qualified teachers, braille literacy has declined since the law took effect.[11] Braille literacy rates have improved slightly since the bill was passed, in part because of pressure from consumers and advocacy groups that has led 27 states to pass legislation mandating that children who are legally blind be given the opportunity to learn braille.[13]

In 1998–99, there were approximately 55,200 legally blind children in the United States, but only 5,500 of them used braille as their primary reading medium.[14][15] Early Braille education is crucial to literacy for a visually impaired child. A study conducted in the state of Washington found that people who learned braille at an early age did just as well, if not better, than their sighted peers in several areas, including vocabulary and comprehension. In the preliminary adult study, while evaluating the correlation between adult literacy skills and employment, it was found that 44% of the participants who had learned to read in braille were unemployed, compared to the 77% unemployment rate of those who had learned to read using print.[16] Currently, among the estimated 85,000 blind adults in the United States, 90% of those who are braille-literate are employed. Among adults who do not know braille, only 33% are employed.[11] Statistically, history has proven that braille reading proficiency provides an essential skill set that allows visually impaired children not only to compete with their sighted peers in a school environment, but also later in life as they enter the workforce.[13]

United Kingdom

Though braille is thought to be the main way blind people read and write, in Britain (for example) out of the reported 2 million visually impaired population, it is estimated that only around 15–20 thousand people use braille.[17] Younger people are turning to electronic text on computers with screen reader software instead, a more portable communication method that they can also use with their friends. A debate has started on how to make braille more attractive and for more teachers to be available to teach it.

Braille transcription


Although it is possible to transcribe print by simply substituting the equivalent braille character for its printed equivalent, in English such a character-by-character transcription (known as uncontracted braille) is only used by beginners.

Braille characters are much larger than their printed equivalents, and the standard 11" by 11.5" (28 cm × 30 cm) page has room for only 25 lines of 43 characters. To reduce space and increase reading speed, most braille alphabets and orthographies use ligatures, abbreviations, and contractions. Virtually all English Braille books are transcribed in this contracted braille, which adds an additional layer of complexity to English orthography: The Library of Congress's Instruction Manual for Braille Transcribing[18] runs to over 300 pages and braille transcribers must pass certification tests.

Fully contracted braille is known as Grade 2 Braille. There is an intermediate form between Computer Braille—one-for-one identity with print—and Grade 2, which is called Grade 1 Braille. In Grade 1 the capital-sign and Number sign are used, and most punctuation marks are shown using their Grade 2 values.

The system of contractions in English Braille begins with a set of 23 words which are contracted to single characters. Thus the word but is contracted to the single letter b, can to c, do to d, and so on. Even this simple rule creates issues requiring special cases; for example, d is, specifically, an abbreviation of the verb do; the noun do representing the note of the musical scale is a different word, and must be spelled out.

Portions of words may be contracted, and many rules govern this process. For example, the character with dots 2-3-5 (the letter "f" lowered in the braille cell) stands for "ff" when used in the middle of a word. At the beginning of a word, this same character stands for the word "to"; the character is written in braille with no space following it. (This contraction was removed in the Unified English Braille Code.) At the end of a word, the same character represents an exclamation point.

Some contractions are more similar than their print equivalents. For example, the contraction , meaning 'letter', differs from , meaning 'little', only in adding one dot to the second : little, letter. This causes greater confusion between the braille spellings of these words and can hinder the learning process of contracted braille.[19]

The contraction rules take into account the linguistic structure of the word; thus, contractions are generally not to be used when their use would alter the usual braille form of a base word to which a prefix or suffix has been added. Some portions of the transcription rules are not fully codified and rely on the judgment of the transcriber. Thus, when the contraction rules permit the same word in more than one way, preference is given to "the contraction that more nearly approximates correct pronunciation."

Grade 3 Braille[20] is a variety of non-standardized systems that include many additional shorthand-like contraction. They are not used for publication, but by individuals for their personal convenience.

Braille translation software

When people produce braille, this is called braille transcription. When computer software produces braille, this is called braille translation. Braille translation software exists to handle most of the common languages of the world, and many technical areas, such as math, music, and tactile graphics.

Braille-reading techniques

Since braille is one of the few writing systems where tactile perception is used, as opposed to visual perception, a braille reader must develop new skills. One skill important for braille readers is the ability to create smooth and even pressures when running one's fingers along the words. There are many different styles and techniques used for the understanding and development of braille, even though a study by B. F. Holland[21] suggests that there is no specific technique that is superior to any other.

Another study by Lowenfield & Abel[22] shows that braille could be read "the fastest and best... by students who read using the index fingers of both hands." Another important reading skill emphasized in this study is to finish reading the end of a line with the right hand and to find the beginning of the next line with the left hand simultaneously. One final conclusion drawn by both Lowenfield and Abel is that children have difficulty using both hands independently where the right hand is the dominant hand. But this hand preference does not correlate to other activities.

International uniformity

Main article: International uniformity of braille


When braille was first adapted to languages other than French, many schemes were adopted, including mapping the native alphabet to the alphabetical order of French – e.g. in English W, which was not in the French alphabet at the time, is mapped to braille X, X to Y, Y to Z, and Z to the first French accented letter – or completely rearranging the alphabet such that common letters are represented by the simplest braille patterns. Needless to say, mutual intelligibility was greatly hindered by this state of affairs. In 1878, the International Congress on Work for the Blind, held in Paris, proposed an international braille standard, where braille codes for different languages and scripts would be based, not on the order of a particular alphabet, but on phonetic correspondence and transliteration to Latin.[23]

This unified braille has been applied to the languages of India and Africa, Arabic, Vietnamese, Hebrew, Russian, and Armenian, as well as nearly all Latin-script languages. Greek, for example, gamma is written as Latin g, despite the fact that it has the alphabetic position of c; Hebrew bet, the second letter of the alphabet and cognate with the Latin letter b, is sometimes pronounced /b/ and sometimes /v/, and is written b or v accordingly; Russian ts is written as c, which is the usual letter for /ts/ in those Slavic languages that use the Latin alphabet; and Arabic f is written as f, despite being historically p, and occurring in that part of the Arabic alphabet (between historic o and q).

Other braille adaptations

Other systems for assigning value to braille patterns are also followed, including the simple mapping of the alphabetical order onto the original French order. Some systems of braille start with unified braille, and then diverge significantly based on the phonology and structure of the target languages, while still other braille systems are completely novel, adopting positional forms, or even syllabic braille cells composed of separate vowel and consonant patterns.

In the various Chinese systems, traditional braille values are used for initial consonants and the simple vowels. In both Mandarin and Cantonese Braille, however, characters have different readings depending on whether they are placed in syllable-initial (onset) or syllable-final (rime) position. For instance, the cell for Latin k, , represents Cantonese k (g in Yale and other modern romanizations) when initial, but aak when final, while Latin j, , represents Cantonese initial j but final oei.

Novel systems of braille mapping include Korean, which adopts separate syllable-initial and syllable-final forms for its consonants, explicitly grouping braille cells into syllabic groups in the same way as hangul. Japanese, meanwhile, combines independent vowel dot patterns and modifier consonant dot patterns into a single braille cell – an abugida representation of each Japanese mora.

Uses

The current series of Canadian banknotes has a tactile feature consisting of raised dots that indicate the denomination, allowing bills to be easily identified by visually impaired people. It does not use standard braille; rather, the feature uses a system developed in consultation with blind and visually impaired Canadians after research indicated that braille was not sufficiently robust and that not all potential users read braille. Mexican bank notes, Indian Rupee notes, Israeli New Shekel notes[24] and Russian Ruble notes also have special raised symbols to make them identifiable by the visually impaired.

In India there are instances where the parliament acts have been published in braille, such as The Right to Information Act.[25]

In the United States, the Americans with Disabilities Act of 1990[26] requires various building signage to be in braille.

Unicode

Main article: Unicode braille patterns

Braille was added to the Unicode Standard in September, 1999 with the release of version 3.0.

The Unicode block for braille is U+2800 ... U+28FF:

Braille PatternsUnicode.org chart (PDF)
  0 1 2 3 4 5 6 7 8 9 A B C D E F
U+280x
U+281x
U+282x
U+283x
(end of cell-6 pattern)
U+284x
U+285x
U+286x
U+287x
U+288x
U+289x
U+28Ax
U+28Bx
U+28Cx
U+28Dx
U+28Ex
U+28Fx
Notes
1.^ As of Unicode version 6.3

See also

Notes

References

External links

  • Association Valentin Haüy
  • Alternate Text Production Center

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.