EBU Euro Group

Users’ specifications for vocal converters with large display and large keys

The following guidelines have been developed jointly by the EBU Euro Group - euro working group of the European Blind Union - the EBU Commission on Technical Devices and Services and the EBU Commission on the Activities of Partially Sighted people, as well as the technological departments of RNIB, ONCE and FFVI. The developed euro converter will still need to be tested with end-users to prove its effectiveness. User testing facilities with visually impaired people are available on a consultancy basis.

1. Background
   
   
2. Familiar Features
   
   
3. General features
   
   
4. Vocal features
   
   
5. Keypad Features
   
   
6. Display
   
   
7. Documentation
   
   

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Visual impairment is one of the major age-related disabilities. Nearly 2% of the population of the European Union, i.e. about 7.4 million people, are assumed to have a significant visual disability. The majority of these visually impaired people are over the age of 65. Moreover, the number of elderly persons who have suffered partial sight loss, without being classified as partially sighted, may be quite considerable. It is also not unusual for elderly persons to have additional disabilities, such as problems with dexterity or impaired hearing or touch. It is therefore important for vocal features as well as good readability and good manageability, features to be considered when developing euro converters for use by visually impaired people.







Basically, euro converters designed for visually impaired persons should provide the same functions and guarantees as euro converters for sighted people.

• Conversion from one national currency into euro and vice-versa (exchange rate pre-programmed and not modifiable by the user)
• Conversion and rounding up, in accordance with EU regulations
• Must conform to CE safety regulations
• Reliability and technical excellence
• Lifetime of at least 3 years with normal use
• External features:
  1. pocket-size (as small as possible considering other requirements)
  2. shock resistance
  3. light weight

User friendliness is a definite must.

• The casing should be made out of non-shiny material.
• There should be a switch on function; i.e. the converter should not remain permanently switched on ().
• A non-removable hard cover () is strongly recommended.
• A delay system on the on key is not advisable ().
• An automatic switch off function is not advisable (). Connection of the closure of the cover to automatic switch off of the converter is recommended.
• (On/off) setting selection is recommended for the display.
• (On/off) setting selection is necessary for the speech function ().
• It is recommended that switches for setting both the display and speech should be on the side of the converter ().
• A non-volatile memory is required, as the Euro conversion rate should remain programmed when replacing batteries and switching off the converter.
• Replacement of batteries () should be made easy for an elderly visually impaired user with loss of dexterity.
• It is recommended to include simple calculation facilities in the converter ().

The vocal features addressed concern speech output, not speech input ().

• It is recommended that each device should speak only one language.
• Echo of confirmation on all functions and figures is required, including the “on” function.
• A repeat speech key is needed (repeat last speech).
• Digitised speech is recommended. The specification for speech is 64 Kbps.
• A low-pitched (), clear, calm voice is recommended. It is advisable to be careful about regional accents.
• Pitch control is recommended ().
• Volume control is needed. Progressive (stepless) volume control is not a requirement.
• An earphones jack socket should be included, to enable connection of an optional (single ear) earphone ().
• Full numbers should be spoken out, rather than figures ()
• A real speech off selection is necessary. The same knob or slide used for volume control can however be used for switching off the speech. Tactile feedback is then needed (e.g. a click after the lowest volume setting).

1. Keys should not have dual functions (for user friendliness); exception is made for the on key, which can also have a clear all function, as on most calculators.
   
   
2. 5 groups of keys : numeric pad, operators' pad, function keys, national currency/euro conversion keys, setting keys. These groups of keys should be clearly differentiated :
   
   • By their shape and/or their size and/or their texture
   • By the use of colours and/or outlines ()
   • By spacing between the numeric and the operators and function pads
   • By a different spacing between the numeric keys and the function keys Recommended spaces between keys are:
     -Number pad: horizontal spacing: min. 3 mm, vertical spacing: min. 5 mm
     -Function pad: horizontal spacing: min. 5 mm, vertical spacing: min. 5 mm
     
   
   
3. Keys :
   • Good contrast is required between buttons and background. Light/dark colour contrast is recommended ()
   • Keys should preferably be flat (not rounded on the top)
   • It is advisable for keys to be made of non-slip material
   • Recommended minimum dimensions for figure keys: round keys: min. 10 mm diameter; square keys: min. 10 x 10 mm; rectangular keys: larger than high.
   • Recommended key height: 1-3 mm.
   
   
4. Text on the keys :
   • It is advisable to have the text on the keys rather than next to the keys; under no circumstances should certain keys with text on them be combined with keys that have text alongside them.
   • Good contrast is required between text or figures and buttons. Light/dark colour contrast is recommended.
   • Required font is simple Helvetica or Arial or Tiresias screenfont (), as large as possible according to the key size, with a minimum size of 14 to 16 points
   • It is recommended to have a combination of a first letter in upper case, with following letters in lower case. Capital letters only should be avoided at all times (except where only one letter is used).
   • Text is required to be as large as possible. Abbreviations can be used as long as they are understandable and explained in the instructions.
   • It can be recommended, though it is not required, to have raised symbols on some of the function keys (); if any, the tactile marking should in no way prevent the easy reading of printed symbols.
   
   
5. Pressure to be exercised on the keys :
   • Keys should not be touch keys ()
   • It is recommended that the pressure required to operate the keys be the same for all keys, even for larger ones.
   • Tactile feedback is required on activating any key
   
   
6. Numeric pad
   The layout of the numeric pad should be standard :
   • The 0 key should be the same size as the other digit keys and should be placed below the “1” key.
   • If a 00 key is needed, it should be same size as the other digit keys and placed below the “2” key.
   • The decimal point should be same size as the digit keys and should be placed below the “2” key (if no “00” key) or below the “3” key (if the “00” key is below the “2” key).
   • A single raised dot is required on the 5 key; it should be positioned so as to not reduce legibility.
   • It is advisable not to have a mark on the 1 key.
   
   
7. Operators' pad :
   • 4 operators and an equal key
   
   
8. Function pad :
   • The on key should be easy to find and identify, no matter its shape or size. It can be used as a clear all key, as on most calculators.
   • A correction mode of the last entered digit is required : a clear last digit key. The clear last digit function should be clearly differentiated from the clear all function ().
   • A repeat key is needed, i.e. repeat last speech.
   • A learn mode key would be very useful ().
   
   
9. Conversion keys :
   • 1 Euro key
   • 1 national currency key
   
   
10. Setting keys/switches :
    • Display on/off
    • Volume control, possibly with volume on/off
    • Volume on/off if not combined with volume control
    • Headphone jack socket
    • Set currency key for the user to programme the other national currency key

• N.B.: setting selection of the display (on/off) is advisable.
• It is recommended that the display be high enough for no magnification (display setting) to be necessary. Specification: minimum height of the figures is 10 mm.
• The required font is simple Helvetica or Arial or Tiresias screenfont.
• LED technology is highly recommended. The display should have high contrast: black background and lit figures. Its surface should not be reflective.
• Indication of the currency on the display (and in speech) is advisable.
• It is necessary for the number of digits planned for in the display to be sufficient to always display the numbers in full.
• Recommendations for digits :
  1. Digits should be purified; e.g.: digit 0 should be a circle and not include any additional flourishes inside the circle.
  2. There should be clear spacing in between digits; recommendation: 2 mm for 10-mm high digits.
  3. Spacing between the thousands: 3 mm
  4. Decimals should be distinguishable from the full number.

• Clearly written instruction booklets are required in the national language and in large print. The documentation should also be available in the other formats adapted to visual impairment, i.e. Braille and audiocassette.
• The documentation should also include information for the user about the overall layout of the euro converter, the layout of the keypads and the abbreviations and tactile symbols used on the function keys.

Documentation: ‘See it right’: Clear Print Guidelines, RNIB