Chapter 4: Hardware

  1. 401 General
  2. 402 Closed Functionality
  3. 403 Biometrics
  4. 404 Preservation of Information Provided for Accessibility
  5. 405 Flashing
  6. 406 Standard Connections
  7. 407 Operable Parts
  8. 408 ICT with Two Way Voice Communication
  9. 409 Caption Processing Technology
  10. 410 Video Description Processing Technology
  11. 411 User Controls for Captions and Video Description

401 General

401.1 Scope.  The provisions of Chapter 4 shall apply where required by Chapter 2 or where referenced by a requirement in this document.

402 Closed Functionality

402.1 General.  Except for personal headsets and audio loops, ICT with closed functionality shall be operable without requiring the user to attach assistive technology and shall conform to 402.

Advisory 402.1 General.  Self-service machines, information kiosks, set-top boxes, and devices like printers, copiers, fax machines, and calculators have closed functionality because their functionality is self-contained.  Their design precludes the user from adding peripherals or software to them.

ICT has closed functionality for many reasons.  These reasons include design or policy.  ICT may have closed functionality in practice even though the manufacturer did not design or develop ICT to be closed.  Computers which are “locked down” to the extent that end users cannot adjust settings are functionally closed.

402.2 Speech Enabled.  ICT shall be speech enabled.  Operating instructions and orientation, visible transaction prompts, user input verification, error messages, and all displayed information for full use shall be accessible to and independently usable by individuals with vision impairments.  Speech shall be delivered through a mechanism that is readily available to all users, including, but not limited to, an industry standard connector or a telephone handset.  Speech shall be recorded or digitized human, or synthesized.  Speech shall be coordinated with information displayed on the screen.

Exceptions:  1. Audible tones shall be permitted instead of speech for visible output that is not displayed for security purposes, including, but not limited to, asterisks representing personal identification numbers.

2.  Advertisements and other similar information shall not be required to be audible unless they convey information that can be used in the transaction being conducted.

402.2.1 User Control.  Speech for any single function shall be automatically interrupted when a transaction is selected.  Speech shall be capable of being repeated and paused.

402.3 Volume Control.  ICT shall provide volume control complying with 402.3.

402.3.1 Private Listening.  Where speech required by 402.2 is delivered through a mechanism for private listening, ICT shall provide a mode of operation for controlling the volume.

402.3.2 Speaker Volume.  Where sound is delivered through speakers on ICT, incremental volume control shall be provided with output amplification up to a level of at least 65 dB.  Where the ambient noise level of the environment is above 45 dB, a volume gain of at least 20 dB above the ambient level shall be user selectable.  A function shall be provided to automatically reset the volume to the default level after every use.

402.4 Characters.  Characters displayed on the screen shall be in a sans serif font.  Characters shall be 3/16 inch (4.8 mm) high minimum based on the uppercase letter “I”.  Characters shall contrast with their background with either light characters on a dark background or dark characters on a light background.

403 Biometrics

403.1 General.  Where provided, biometrics shall not be the only means for user identification or control.

Exception:  Where at least two biometric options that use different biological characteristics are provided, ICT shall be permitted to use biometrics as the only means for user identification or control.

Advisory 403.1 General Exception.  Biometrics use biological characteristics for user identification or control.  Examples of biometrics used for identification or control are fingerprints, retinal scans, iris patterns, voice prints, facial recognition, and veins in a hand.

Biometrics that are restricted to a single biological characteristic pose a significant barrier to individuals with disabilities who do not possess that specific biological characteristic.

Biometric methods based on dissimilar biological characteristics increase the likelihood that individuals with disabilities possess at least one of the specified biological characteristics.  Examples of dissimilar biological characteristics are fingerprints, eye retinal patterns, voice, and face.

Examples of biometrics that rely upon dissimilar biological characteristics are voice recognition and face recognition.  Examples of biometrics that rely upon similar biological characteristics are finger printing and thumb scans.

This provision requires ICT that uses biometrics to provide for two (or more) dissimilar biological characteristics.

404 Preservation of Information Provided for Accessibility

404.1 General.  ICT that transmits or converts information or communication, shall not remove non-proprietary information provided for accessibility or shall restore it upon delivery.

Advisory 404.1 General.  This provision applies to conversion techniques, such as encoding, signal compression, and format transformation.  Examples of ICT that encode, compress, or transform include firewalls, routers, and gateways.

One example of ICT preserving information provided for accessibility is a media player that displays embedded captions from a captioned video and does not strip out the captioning.

Another example of ICT preserving information provided for accessibility is converting a document into a new format while retaining information about the identity, operation, and state of the interface elements.

This provision does not require the addition or translation of information.  For example, this is not a requirement to change voice mail to text or to vocalize captions.

405 Flashing

405.1 General.  Where ICT emits lights in flashes, there shall be no more than three flashes in any one second period.

Exception:  Flashes that do not exceed the general flash and red flash thresholds defined in WCAG 2.0 (incorporated by reference in Chapter 1) are not required to conform to 405.

406 Standard Connections

406.1 General.  Where connection points are provided, at least one of each type of connection shall conform to industry standard non-proprietary formats.

Advisory 406.1 General.  The intent of this provision is to ensure compatibility with assistive technologies by requiring the use of standard connections on ICT.

Examples of connection points include expansion slots, ports, and connectors for cables.

Industry standard non-proprietary formats include wireless connections to ICT, such as infrared (IR) and Bluetooth.

407 Operable Parts

407.1 General.  Where provided, operable parts of ICT shall conform to 407.

Exception:  Operable parts of ICT that is portable shall not be required to conform to 407.13 through 407.16

407.2 Contrast.  Where provided, keys and controls shall contrast visually from background surfaces.  Characters and symbols shall contrast visually from background surfaces.  Visual contrast shall be either light-on-dark or dark-on-light.

407.3 Tactilely Discernible.  At least one tactilely discernible input control shall be provided for each function.  Where provided, key surfaces not on active areas of display screens shall be raised above surrounding surfaces.  Where touch or membrane keys are the only method of input, each key shall be tactilely discernible from surrounding surfaces and adjacent keys.

407.3.1 Identification.  Operable parts shall be tactilely discernible without activation.

407.4 Key Repeat.  Where an alphabetic keyboard with key repeat is provided, the delay before the key repeat shall be adjustable to at least 2 seconds and the key repeat rate shall be adjustable to 2 seconds per character.

407.5 Numeric Keys.  Where provided, numeric keys shall be arranged in a 12-key ascending or descending telephone keypad layout.  The number five key shall be tactilely distinct from the other keys.

Advisory 407.5 Numeric Keys.  A telephone keypad and a keypad on a computer keyboard differ in one significant feature, ascending versus descending numerical order of the layout.  Both types of keypad layout conform to this provision.

407.6 Timed Response.  Where a timed response is required, ICT shall alert the user by touch or sound and provide the user with the opportunity to indicate that more time is needed.

407.7 Status Indicators.  Where provided, status indicators, including all locking or toggle controls or keys, shall be discernible either through touch or sound.

407.8 Color.  ICT shall not use color coding as the only means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.

Advisory 407.8 Color.  This provision allows ICT to use color.  One example is an electronic form with required and optional fields.  Instructions at the beginning of this form state that required fields are labeled with an asterisk and appear in red text.  In this example, the asterisk is the non-color dependent visual means of conveying information.

407.9 Operation.  Operable parts shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist.  The force required to activate operable parts shall be 5 pounds (22.2 N) maximum.

407.10 Privacy.  ICT shall provide the opportunity for the same degree of privacy of input and output to all individuals.

407.11 Receipts, Tickets, and Transactional Outputs.  Where receipts, tickets, or other outputs are provided as a result of a transaction, speech output shall include all information necessary to complete or verify the transaction.

Advisory 407.11 Receipts, Tickets, and Transactional Outputs.  The information necessary to complete or verify a transaction depends on the nature of the transaction and the type of machine.

Receipts, tickets, and similar transactional output usually are printed, but this is not always the case.  For example, a theater ticket might be transferred to a smart phone or PDA.  Regardless of the delivery method, the machine must convey audibly to the user the information provided in receipts, tickets and other similar transactional outputs that is necessary to complete and verify a transaction.

Exceptions:  1. Machine location, date and time of transaction, customer account number, and the machine identifier shall not be required to be audible.

2.  Information that duplicates information available on-screen and already presented audibly shall not be required to be repeated.

3.  For ticketing machines, printed copies of itineraries and maps shall not be required to be audible.

407.12 Keys, Tickets and Fare Cards.  Where keys, tickets or fare cards are provided, keys, tickets and fare cards shall have an orientation that is tactilely discernible if orientation is important to further use of the key, ticket or fare card.

Advisory 407.12 Keys, Tickets and Fare Cards.  Examples of keys include electronic pass cards and identification badges which are read by machines.  Examples of ways to provide an orientation that is tactilely discernible include braille labels, off-center punch holes, and notching a corner.

407.13 Clear Floor Space.  A clear floor or ground space conforming to 36 CFR Part 1191 Appendix D, Section 305 shall be provided.

407.14 Height.  Operable parts of ICT shall be placed within one or more of the reach ranges conforming to 36 CFR Part 1191 Appendix D, Section 308.

Advisory 407.14 Height.  This provision applies to reach ranges for either a forward or a side approach.

407.15 Visibility.  Where a display screen is provided, it shall be visible from a point located 40 inches (1015 mm) above the center of the clear floor space in front of the ICT.

407.16 Braille Instructions.  Where speech is required by 402.2, braille instructions for initiating the speech mode of operation shall be provided.  Braille shall conform to 36 CFR Part 1191 Appendix D, Section 703.3.

408 ICT with Two Way Voice Communication

408.1 General.  ICT that provides two way voice communication shall conform to 408.

408.2 Volume Gain.  For transmitted voice signals, ICT shall provide a gain adjustable to a minimum of 18 dB.  For incremental volume control, ICT shall provide at least one intermediate step of 12 dB gain.

408.3 Magnetic Coupling.  Where ICT delivers output by an audio transducer which is typically held up to the ear, ICT shall provide a means for effective magnetic wireless coupling to hearing technologies.

408.4 Minimize Interference.  Interference with hearing technologies (including hearing aids, cochlear implants, and assistive listening devices) shall be reduced to the lowest possible level and shall conform to 408.4.

408.4.1 Cellular and PCS Handsets.  ICT in the form of cellular and Personal Communication Service (PCS) handsets shall conform to ANSI/IEEE C63.19-2011 (incorporated by reference in Chapter 1).

408.4.2 Digital Wireline.  ICT in the form of digital wireline devices shall conform to TIA 1083, Telephone Terminal Equipment Handset Magnetic Measurement Procedures and Performance Requirements (incorporated by reference in Chapter 1).

408.5 ITU-T Recommendation G.722.  ICT shall transmit and receive speech that is digitally encoded in the manner specified by ITU-T Recommendation G.722 for encoding and storing audio information (incorporated by reference in Chapter 1).

Exception:  Where ICT is a closed system, conformance to standards other than ITU-T Recommendation G.722 shall be permitted where equivalent or better acoustic performance is provided and where conversion to ITU-T Recommendation G.722 at the borders of the closed system is supported.

Advisory 408.5 ITU-T Recommendation G.722 Exception.  One example of a closed system is a telephone network in a federal multiple facility site which enables calls to be placed between buildings and departments within that site, but is not used to receive or make calls outside of that site.

408.6 Real Time Text Functionality.  Where ICT provides real time voice communication, ICT shall provide real time text functionality and shall conform to 408.6.

408.6.1 Display of Real Time Text.  Where provided, multi-line displays shall be compatible with real time text systems used on the network.

408.6.2 Text Generation.  Where provided, features capable of text generation shall be compatible with real time text systems used on the network.

408.6.3 Interoperability.  Where ICT interoperates outside of its closed system, or where ICT connects to other systems, ICT shall conform to 408.6.3.1 or 408.6.3.2.

408.6.3.1 PSTN.  Where ICT interoperates with the PSTN (Public Switched Telephone Network), real time text shall conform to the TIA 825-A (incorporated by reference in Chapter 1) Baudot standard for TTY signals at the PSTN interface.

408.6.3.2 VoIP Using SIP.  Where ICT interoperates with Voice over Internet Protocol (VoIP) products or systems using Session Initiation Protocol (SIP), they shall support transmission of real time text that conforms to RFC 4103 (incorporated by reference in Chapter 1).

408.6.4 Real Time Text Compatibility.  Voice mail, auto-attendant, and interactive voice response telecommunications systems shall be compatible with real time text that conforms to 408.6.3.

408.7 Caller ID.  Where provided, caller identification and similar telecommunications functions shall be available as text or in an audio form.

408.8 Video Communication.  Where ICT that provides two way voice communication includes real time video functionality, the quality of the video shall be sufficient to support communication using sign language.

409 Caption Processing Technology

409.1 General.  Where ICT displays or processes video with synchronized audio, ICT shall conform to 409.1.1 or 409.1.2.

409.1.1 Decoding of Closed Captions to Open Captions.  Where audio-visual players and displays process video with synchronized audio information, players and displays shall decode closed caption data and pass on an open-captioned signal to the video display.

409.1.2 Pass Through of Closed Caption Data.  Where audio-visual players and displays process video with synchronized audio information, players and displays shall pass through closed caption data to the video display for decoding as displayed text.  Cabling and ancillary equipment shall not block the pass through of closed caption data.

410 Video Description Processing Technology

410.1 General.  Where ICT displays or processes video with synchronized audio information, ICT shall provide a mode of operation that plays audio information associated with video description.

410.1.1 Digital Television Tuners.  Where video description is played through digital television tuners, the tuners shall conform to ATSC A/53 Digital Television Standard, Part 5 (2010) (incorporated by reference in Chapter 1).  Digital television tuners shall provide processing of video description when encoded as a Visually Impaired (VI) associated audio service that is provided as a complete program mix containing video description according to the A/53 standard developed by the Advanced Television Systems Committee (ATSC) (incorporated by reference in Chapter 1).

411 User Controls for Captions and Video Description

411.1 General.  Where ICT displays video with synchronized audio content, ICT shall provide user controls for closed captions and video description conforming to 411.1.

411.1.1 Caption Controls.  Where user controls are provided for the selection of volume, ICT shall provide user controls for the selection of captions in at least one location that is comparable in prominence to the location of the user controls for volume.

411.1.2 Video Description Controls.  Where user controls are provided for the selection of channels, ICT shall provide user controls for the selection of video description in at least one location that is comparable in prominence to the location of the user controls for channels.