Accessible Telecommunications Product Design Tutorial

Contents

Part I

  • Background
  • Purpose of the Guide
  • Organization of the Document

Part II

  • Subpart B Provisions
  • Applicability of provisions from multiple technical areas
  • 1194.23(a) TTY Connection/Microphones
  • 1194.23(b) TTY Signal Protocols
  • 1194.23(c)  Voice Mail, Auto-attendant and Interactive Voice Response Systems
  • 1194.23(d) Time Interval Alerts
  • 1194.23(e) Caller ID and Similar Functions
  • 1194.23(f)  Volume Control
  • 1194.23(g) Automatic Volume Reset
  • 1194.23(h) Hearing Aid Compatibility
  • 1194.23(i)  Minimized Interference
  • 1194.23(j) Transmission/Conducting Information
  • 1194.23(k) Controls & Key

Part III       

  • References
    Section 508 Accessible Telecommunications
    Product Design Technical Assistance

I.  BACKGROUND Amendments to Section 508 of the Rehabilitation Act were passed in 1998.  Standards developed by the Access Board for Section 508 were published in December 2000.  A set of technical assistance guides were developed by the Arial">Access Board and made available during the Spring of 2001, shortly before the date of enforcement of the 508 standards.  These guides are for the benefit of Federal government procurement officers, are general in nature and are available through the Access Board’s website.  Over time, as the industry and others became more familiar with the standards, inquiries became more technical in nature.  This justified the need to develop a more advanced technical assistance document. Purpose of the Guide This document is intended to provide technical guidance for designers of telecommunications products, with the understanding that Section 508 does not impose any requirements on manufacturers but instead requires agencies and departments of the Federal government to comply with accessibility regulations when procuring, developing, using, or maintaining electronic and information technology.  It analyzes the standards issued by the Access Board for Section 508, and gives background and parameters useful in developing telecommunications products that conform to the 508 standards.  This technical assistance document is not a revision of the 508 standards.  That could only come about through a rulemaking process.  Instead, by explaining norms in product design and by referencing industry consensus standards, this document is intended to inform engineers who may be unfamiliar with specifications for such common terms as TTY and Baudot.  Organization of the DocumentThe following structure is used in this document to organize the material for each provision:

  1. 508 Provision – Quotes the provision verbatim from 36 CFR 1194.23.  The short headings for the provisions are taken from the actual text of the provisions and are consistent with the headings used in previously developed Access Board 508 technical assistance guides.  For example, provision 1194.23 (j) is called “Transmitting/Conducting Information.”
     
  2. Introduction & Background – Gives an introduction to the provision and the issue being addressed by the rule.
     
  3. Design Guidance – Uses a question and answer format, in most provisions, to address the interests of product designers.  This section provides further technical information and gives measurable targets.  Where applicable, examples of implementation methods are given.  It is imperative that Federal agencies understand that these methods illustrated are not the only approaches for reaching accessibility goals.
     
  4. Requirements and Recommendations – Wraps-up discussion of the provision. This last section helps identify the requirements of the Section 508 provision.  In addition, it gives recommendations on ways that fuller accessibility may be provided:
  • Provision Requirementsare design elements necessary for product conformance to the Section 508 provision.
  • Recommended Practices are design approaches that augment or exceed the 508 provision requirement and enhance usability and accessibility.

II.  SUBPART B PROVISIONSApplicability Products that provide telecommunications functionality must comply with the provisions for Telecommunications Products, §1194.23.  For products with multiple functions, the “Telecommunications Products” provisions apply only to the telecommunications functions of those products.  Other 508 technical provisions may apply to the other functions. To quote from the preamble to the Section 508 Standards Final Rule:[1]

 “Electronic and information technology covered by section 508 must comply with each of the relevant sections of this part [1194]. For example, a computer and its software programs would be required to comply with §1194.26, Desktop and portable computers, §1194.21, Software applications and operating systems, and the functional performance criteria in §1194.31.”

The products affected by the provisions governing Telecommunications Products extend from the traditional telephone to a wide variety of new and emerging products.  The convergence of telecommunications and information technology is blurring the line between different product types as a variety of new and innovative products are created.  Section 508 was designed to be flexible, assuring that all electronic and information technology procured by the government is accessible and allowing clear and common sense application of its various provisions.  Common sense and flexibility should be utilized in interpreting the suggested guidance delineated within this technical assistance document. Therefore, provisions from both Subpart B as well as Subpart C of the 508 standards may apply to certain products or services.  For example, using only 1194.23 (the Telecommunications Products provisions), it is possible to design a touch screen-only product (with no keypad and no voice output) that would be completely inaccessible to people who are blind.  However, applying the provisions from 1194.31 (Functional Performance Criteria) would make the product conforming to the Section 508 standards. The term “Telecommunications Function” is derived from the definition of telecommunications and related terms.  Both Section 508 (of the Rehabilitation Act) and Section 255 (of the Telecommunications Act) use this definition, which reads:

 Telecommunications: The transmission, between or among points specified by the user, of information of the user's choosing, without change in the form or content of the information as sent and received.

This definition is utilized extensively in law and regulations affecting telecommunications products.  Therefore, there exists substantial legislative, regulatory, and case history defining its terms and scope. Other related definitions, derived from the Telecommunications Accessibility Guidelines for Section 255 of the 1996 Telecommunications Act are:

 Customer premises equipment: Equipment employed on the premises of a person (other than a carrier) to originate, route, or terminate telecommunications.  Telecommunications equipment: Equipment, other than customer premises equipment, used by a carrier to provide telecommunications services, and includes software integral to such equipment (including upgrades).  Telecommunications service: The offering of telecommunications for a fee directly to the public, or to such classes of users as to be effectively available directly to the public, regardless of the facilities used.

Again, products generally have primary functions that will be covered by one of the six technical areas in Subpart B.  However, products often have features that may be covered in other sections of Subpart B as well as Subpart C.  Some examples of how the Telecommunications Products provisions should be applied will now be given to assist in further clarifying the correct application of these provisions.  Three types of products will be used to illustrate how the provisions should apply.  The first example is a typical desktop telephone with answering machine capability.  The second is a self-contained, single-function FAX machine.  The third is a complex “All-in-One” machine that includes FAX, scanner, copier, and printer.  The unit connects to a personal computer and contains software to be loaded on the personal computer. 1. A typical desktop telephone with answering machine is clearly covered by section 1194.23 because its primary function is to provide telecommunications functionality.  All parts of 1194.23 apply to this product, as do all parts of 1194.31.  Provisions from other technical sections of 508 may also apply based on the telephone design and features.  
2. A second example is a self-contained, stand-alone FAX machine without the capability to make a voice call (i.e., the unit has no handset or microphone for a voice call.).  However, the unit has a speaker to enable the user to hear the line status.  This unit is both a self contained, closed product and a telecommunications product.  From Subpart B and C of the 508 standards, 1194.23, 1194.25, and 1194.31 apply.  From the Telecommunications Products section (1194.23), only provisions ‘e’, “Caller ID; and ‘k’, “Controls and Keys” apply to this product.   Provision 1194.23(e) requires any functions, such as Caller ID, to be accessible, if the product provides such functions.  Provision 1194.23(k) requires that the controls be accessible.  The other provisions of 1194.23 do not apply.  Provisions ‘a’, ‘b’, ‘d’, ‘f’, ‘g’, ‘h’ and ‘i’ from 1194.23 do not apply because voice calls are not supported.  Provision ‘c’ does not apply because there is no voice mail, auto attendant, or interactive voice response involved with the product.  Provision ‘j’ does not apply because there is no accessibility information (e.g., captions) being passed through the FAX machine.  The provisions in §1194.25 (Self Contained, Closed Products) are:

§1194.25(a)   Usability
§1194.25(b)   Timed Responses
§1194.25(c)   Touchscreens and Controls
§1194.25(d)   Biometric Forms/User ID
§1194.25(e)   Auditory Output
§1194.25(f)    Volume Control
§1194.25(g)   Color Coding
§1194.25(h)   Color and Contrast Settings
§1194.25(i)    Screen Flicker
§1194.25(j)    Operable Controls

From the 1194.25 provisions, ‘a’, ‘b’, ‘c’, ‘g’, ‘h’, and ‘i’ apply to this product.  Provision ‘d’ does not apply because no biometric form of identification is being used in this particular example.  Provision ‘e’ does not apply because the product does not deliver voice output.  Provision ‘f’ does not apply because there is no voice output for purposes of a conversation.  Provision ‘j’ does not apply because this is not a freestanding product. Provisions ‘c’, ‘h’, and ‘i’, may not apply depending on whether the product has a display and on the type of display.  A third example is an “All-in-One” machine connected to a personal computer that includes a FAX, scanner, printer, and copier.  This product does not support voice calls.   The product includes software to be loaded on the personal computer.  Therefore, this software must meet the requirements for software (1194.21).  The unit itself is similar to the one in the second example and is covered under the telecommunications products (1194.23) and self contained, closed products (1194.25) provisions, as well as the 1194.31 functional performance criteria. To determine exactly which provisions apply to this “All-in-One” product, the same kind of analysis performed in the example of the stand alone FAX machine would be performed. §1194.23 ProvisionsThe following table quotes verbatim the telecommunications accessibility provisions found in §1194.23, Telecommunications Products.  Headings by each provision are hyperlinked to the discussion of that provision in the document.

 


Section 508 Rule §1194.23 Telecommunications Products
 

TTY Connection/Microphones

§1194.23(a)  
Telecommunications products or systems which provide a function allowing voice communication and which do not themselves provide a TTY functionality shall provide a standard non-acoustic connection point for TTYs. Microphones shall be capable of being turned on and off to allow the user to intermix speech with TTY use.

TTY Signal Protocols

§1194.23(b)  Telecommunications products which include voice communication functionality shall support all commonly used cross-manufacturer non-proprietary standard TTY signal protocols.

Interactive Voice Response Systems

§1194.23(c)   Voice mail, auto-attendant, and interactive voice response telecommunications systems shall be usable by TTY users with their TTYs.

Time Interval Alerts

§1194.23(d)  Voice mail, messaging, auto-attendant, and interactive voice response telecommunications systems that require a response from a user within a time interval, shall give an alert when the time interval is about to run out, and shall provide sufficient time for the user to indicate more time is required.

Caller ID and Similar Functions

§1194.23(e)   Where provided, caller identification and similar telecommunications functions shall also be available for users of TTYs, and for users who cannot see displays.

Volume Control

§1194.23(f)    For transmitted voice signals, telecommunications products shall provide a gain adjustable up to a minimum of 20 dB. For incremental volume control, at least one intermediate step of 12 dB of gain shall be provided.

Automatic Volume Reset

§1194.23(g)  If the telecommunications product allows a user to adjust the receive volume, a function shall be provided to automatically reset the volume to the default level after every use.

Hearing Aid Compatibility

§1194.23(h)  Where a telecommunications product delivers output by an audio transducer which is normally held up to the ear, a means for effective magnetic wireless coupling to hearing technologies shall be provided.

Minimized Interference

§1194.23(i)    Interference to hearing technologies (including hearing aids, cochlear implants, and assistive listening devices) shall be reduced to the lowest possible level that allows a user of hearing technologies to utilize the telecommunications product.

Transmission/Conducting Information

§1194.23(j)    Products that transmit or conduct information or communication, shall pass through cross-manufacturer, non-proprietary, industry-standard codes, translation protocols, formats or other information necessary to provide the information or communication in a usable format.  Technologies which use encoding, signal compression, format transformation, or similar techniques shall not remove information needed for access or shall restore it upon delivery.

Controls & Keys

§1194.23(k)   Products which have mechanically operated controls or keys, shall comply with the following:(1) Controls and keys shall be tactilely discernible without activating the controls or keys.(2) Controls and keys shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. The force required to activate controls and keys shall be 5 lbs. (22.2 N) maximum.(3) If key repeat is supported, the delay before repeat shall be adjustable to at least 2 seconds. Key repeat rate shall be adjustable to 2 seconds per character.(4) The status of all locking or toggle controls or keys shall be visually discernible, and discernible either through touch or sound.

  


TTY Connection/Microphones508 Provision §1194.23(a)  Telecommunications products or systems which provide a function allowing voice communication and which do not themselves provide a TTY functionality shall provide a standard non-acoustic connection point for TTYs.  Microphones shall be capable of being turned on and off to allow the user to intermix speech with TTY use. Introduction & Background People with significant hearing or speech disabilities commonly use text-based communication to converse over the telephone.  TTYs (teletypewriters) allow transmission of text conversations by telephone in real time.  This provision addresses two different issues.  One deals with the way a TTY is connected. This is important to ensure signal quality as well as to make the conversation possible in some cases.  The other issue pertains to providing support for certain classes of TTY users who communicate by mixing speech and text on a call. TTYs traditionally have had acoustic modems utilizing couplers on the top of the device. These are frequently used in offices where hearing people answer the telephone.  The acoustic coupling mode allows a hearing call taker to answer in voice and put the handset into the TTY coupler if needed for a TTY call.  Thus, provision of a handset that is compatible with a TTY is often helpful for these situations.  However, a direct connection is often needed for its unique benefits, such as TTY-answering-machine capability and keyboard dialing.  In addition, some TTY models do not have acoustic cups. Another important reason for requiring a direct connection is improved signal quality.  Acoustic coupling is subject to audio interference from noise in the environment.  Also, increasingly, handsets are diverse in design and many do not fit well into standard acoustic couplers.  If an acoustic modem picks up ambient noise while receiving data, it could display unintended characters making the conversation difficult to understand. Therefore, a direct connection enables TTYs to obtain a clearer signal. The requirement enabling the intermix of voice and TTY tones is important because it allows a more efficient use of TTYs by some people, depending on their abilities.  Originally, TTY users would use TTYs for both typing and reading.  Those that could speak, however, quickly determined that (if the other person could hear) they could pick up the receiver when it was their turn to talk and just speak to the other person (who would then type back on their turn). This was much faster and preferred by both sides of the conversation.  The ability to use speech for outgoing and TTY for incoming is often referred to as VCO or voice carry over on the speaker/reader’s end and HCO or hearing carry over on the listener/typer’s end.   This same feature, VCO/HCO, can also be used (but in reverse) by a person with a speech disability.  Again, one person (the person with a speech disability) types and listens (HCO) and the other person speaks and reads (VCO).  Thus VCO and HCO are not two different features – but two parts (the two ends) of the same feature. The person with a disability can be at either end of the conversation (or both – since a deaf speaking person can use VCO/HCO to communicate with a hearing person with a speech disability).   Some TTY telephones incorporate VCO/HCO functionality into the device hardware. VCO/HCO is often used with the Telecommunications Relay Service (TRS).  TRS is a service, mandated under Title IV of the Americans with Disabilities Act, which employs a live operator (known as a Communication Assistant – CA) who facilitates the conversation between people using TTYs and those who do not have TTYs or are not using them.[2]   Sometimes TRS CAs are at the HCO end of the conversation and sometimes they are at the VCO end, depending on the type of disability of the person they are assisting.  That is, there are two different times when the TRS CA conveys the communication in one direction only:

  • In one case, the TRS operator does nothing but type what the 3rd party is saying so the person with the TTY can read it.  (e.g., with a TTY user who is deaf and can speak back directly to the 3rd party.)
  • In the other case, the TRS operator does nothing but read what the person with a TTY is typing so that the 3rd party can hear it. (e.g., with a TTY user who has a speech impairment but can hear the 3rd party speaking.)
  • (NOTE: The relay services also have a newer “Speech to Speech” or STS service where they will re-voice speech for those who can speak, but whose speech is hard for many to understand.)  

 This part of provision 1194.23(a) was necessary to ensure that a telephone system would not inadvertently prevent a telephone mouthpiece microphone from working when a TTY was being used with the telephone.  For example, there have been instances where a cellular telephone has been designed so that its microphone is disabled while the cellular telephone’s headset jack was connected directly to a TTY.  This prevented the TTY user from being able to utilize the VCO option.  Once the TTY is disconnected from the cellular telephone, the cellular telephone mouthpiece returns to normal operation.  A VCO mode in the cellular handset, which permits the microphone to be on while TTY is being received, is one way to meet this requirement. Another aspect of this provision is a requirement that the microphone be capable of being turned on or off.  This enables a user to mute the microphone when receiving TTY tones to minimize introducing ambient noise into the line.  The reason for keeping the line clear of unwanted noise is to minimize interference to TTY tones, which could result in garbled characters on the TTY display.  Some manufacturers may consider developing a method for automating the switching process in the future. Design Guidance • Is my product affected by this provision? This provision applies to products that allow voice communications.  For example, a fax machine with line-monitoring speaker (and no handset or microphone) is one-directional only and therefore, not covered, even though it emits speech, if a person answers the telephone on the other end of the fax call.  However, a fax machine with a handset, enabling a two-way conversation, would be covered.   As the provision states, this does not apply to products, which themselves, already have TTY functionality.  For example, there are telephones on the market which represent a hybrid telephone and TTY designed as one unit. • Why is a non-acoustic connection important? A non-acoustic connection point is important because it allows the TTY user to achieve a lower data error rate than acoustic only connections. • What connectors do TTY’s most commonly use? The most common non-acoustic connection for wireline equipment is an analog PSTN RJ-11 jack.  For cordless and analog wireless use, the non-acoustic connection commonly used is a 2.5 mm headset jack.  For digital wireless, the most common would be a 2.5 mm headset jack that conforms to TIA TSB-121.  Use of the 2.5 mm audio jack carries limitations. Telephones with audio jacks and no RJ-11 jack will not work with many popular office TTY models that only have RJ-11 jacks, including many of the currently available TTYs with printers and answering machines. This limitation is not much of a problem for TTYs that are compatible with wireless telephones; these TTYs are designed for mobility and do not have printers or answering machines, and can be well supported by the 2.5 mm jack.  There has been a migration from analog to digital service.  TTYs are analog-based devices and connect with RJ-11 jacks.  TTYs and the wireline digital network can be damaged if TTYs are incorrectly connected to digital jacks.  A TTY should not be plugged directly into a digital telephone network unless there is an analog jack or an analog converter available.  Even if such a connection point is provided, there remains a possibility that the digital service may garble the TTY characters. • How can voice and TTY tones be intermixed?Under 508, the whole telephone system - including both telephone hardware and telephone service - must support the ability of users to communicate with text in one direction and speech in the other or to intermix speech and TTY tones in either of the directions (as might happen if a person’s speech is sometimes but not always understandable).  Although it would sometimes be advantageous to allow communication in both directions to occur simultaneously without interfering with each other, this provision only requires the telephone system to support the ability for voice and TTY tones to alternate, not to be sent at the same time. Some software and modems allow a computer to function as a TTY and communicate directly over telephone lines.  Section 508 does not require a computer to provide speakers and a microphone for use in telephone conversations.  However, in cases where speakers and a microphone are available for telephone conversations, the system should conform to this provision by allowing speech and TTY tones to be intermixed.  Vendors of such computer products should explain to Federal agencies how computers (when equipped with such assistive software and possibly a telephone) can be connected to the same line or jack to support VCO and HCO for both inbound and outbound calling.  Provision Requirements

  • A standard, non-acoustic connection for TTYs should be provided.
  • The user should be able to turn microphones on and off, so as to intermix speech with TTY signals.

Recommended Practices

  • This provision does not require a telephone to have built-in TTY functionality.  For example, an analog telephone port that allows connection to a TTY is perfectly acceptable to provide assistive technology compatibility. 
  • It is possible to provide equivalent facilitation using TTY emulating software in a personal computer (equipped with a microphone and speakers), but only if the VCO requirement is addressed in the solution.
  • Although this provision does not specifically address the issue of quality necessary for effective communication, voice and TTY signals could be capable of being mixed without garbling of TTY text or reduction of speech quality.
  • Where an analog RJ-11 connector is provided for TTY connectivity, a ring equivalence of 1 is commonly provided (in addition to the 1 ring equivalent provided for the telephone).
  • If the port connects directly to the PSTN, it should conform to the standards for an analog PSTN telephone line (FCC Part 68).
  • Although one of the purposes of this provision is to ensure good signal quality, a TTY direct connection has a secondary benefit of supporting the auto answer ability of TTYs with that feature.  Designers should note that TTYs connected through an audio jack cannot act as answering machines – even if they have answering machine features in them (that work when they are connected through an RJ-11 jack).  To answer a telephone (or act as an answering machine) TTYs need to have a direct connection to the telephone line.
  • It is important that telephones, which provide audio connection points, pass through the ring signal to the connector so that TTYs with built-in signal capability can detect the ringing. The telephone set-up for a TTY needs to be able to activate a flashing light (or, in the case of portable/wireless telephones, vibrating) feature or third party device in order for a TTY user with a hearing loss to know when the telephone is ringing.
  • It would be helpful for there to be a standard mechanism for TTYs to answer the telephone when connected through a 2.5 mm audio connection point so that TTY auto-answer or answering machines can work.

TTY Signal Protocols
508 Provision §1194.23(b)  Telecommunications products which include voice communication functionality shall support all commonly used cross-manufacturer non-proprietary standard TTY signal protocols. Introduction & Background A two-way, real-time text-based telephone service for people with communication disabilities, based upon TTYs, was developed from teletype machines in the 1960s.  The purpose of this provision is to ensure that TTY compatibility (with the signal, not just the connection point) is not overlooked.  Specifically, this provision requires that mainstream telecommunications products be compatible with the traditional or standard TTY code of 45.5 baud Baudot.  Design Guidance • Is my product affected by this provision? This provision applies to all telecommunications products that support 2-way voice communications.   For example, a fax machine with a line monitoring speaker only (but no handset with microphone, and no speakerphone functionality) is only one-directional and therefore, not covered, even though it emits speech and sounds of the person at the other end of the call.  However, a fax machine with handset and microphone, enabling a two-way conversation, would be covered. • What is a TTY and how does it work? A TTY is a text communication terminal that allows people with hearing or speech disabilities to use the telephone.  TIA/EIA 825-A, “A Frequency Shift Keyed Modem For Use On The Public Switched Telephone Network” is the basic standard defining the Baudot TTY.   TTYs (transmitting in 45.5 baud Baudot) that conform to TIA/EIA 825-A are silent when not transmitting.

  • Unlike fax machines and computer modems, these TTYs have no "handshake" procedure at the start of a call, nor do they have a carrier tone during the call.
  •  Although this approach tends to limit the speed of transmission, it has the advantage of permitting TTY tones, DTMF (Dual Tone Multi-Frequency signals, also known as "touch tones"), and voice to be intermixed on the same call.  It also allows TTY calls to be put on hold and to be transferred.

Operation is "half duplex." 

  • Users of older model TTYs needed to take turns transmitting, and typically could not interrupt each other without causing errors in characters received.  (However, users of some of the newer model TTYs that use a proprietary code can, in fact, interrupt one another without a loss of signal quality.)
  • When transmitting in 45.5 baud Baudot, there is no automatic mechanism that lets TTY users know when a character they have typed correctly has been received incorrectly. 

Each TTY character consists of a sequence of seven individual tones.

  • The first tone is always a "start tone" at 1800 Hz.
  • This is followed by a series of five tones, at either 1400 or 1800 Hz, which specify the character.
  • The final tone in the sequence is always a "stop tone" at 1400 Hz.  The "stop tone" is a border that separates this character from the next.
  • Each of the first six tones is 22 milliseconds in duration.  The final "stop tone" is usually 33 milliseconds, but is permitted to be as long as 44 milliseconds.  This means that the duration of each TTY character is at least 165 milliseconds, which works out to approximately six characters per second. (The description of this as a "45.5 Baud" protocol is based on the number of 22-millisecond tones that can be transmitted in one second, not the number of characters.)

Provision Requirements • Telecommunications products which include voice communication functionality should support all commonly used cross-manufacturer non-proprietary standard TTY signal protocols. Recommended Practices • There is no single protocol for testing TTY signals within mainstream telecommunications systems.  For example, there are different issues for TTY over wireless networks than for TTY over VoIP.  However, for evaluating TTY error rates on digital wireless telephones, consider testing protocols developed by the TTY Forum. See: http://www.atis.org/atis/tty/ttyforum.htm.


Voice mail, Auto-attendant and Interactive Voice Response Systems 508 Provision §1194.23(c) Voice mail, auto-attendant, and interactive voice response telecommunications systems shall be usable by TTY users with their TTYs. Introduction & Background Interactive Voice Response Systems (IVRS) have become a common means for agencies to manage their calls.  These services provide a number of functions including voice mail, and increasingly unified messaging, auto-attendant, call routing, information delivery, and interactive voice response.  However, for people who use TTYs, these labor saving services often present barriers.  Moreover, as IVRS replace receptionists, operators and other customer support methods, TTY users may actually lose services they previously relied on and be completely unable to call anyone in an agency (even if the person has a TTY on their desk) because they cannot get through the automated receptionist. Design Guidance • Is my product affected by this provision? This provision applies to all devices that incorporate IVR functionality, such as voice mail systems, auto-attendant, and interactive voice response systems. • How does this provision apply to voice mail systems? Voice mail systems not only need to be fully functional for people who are calling in while using a TTY, but should also be fully functional to people who are subscribers to the voice mail service and use a TTY to access their voice mail service. • What potential methods can be used to meet this provision? There are several potential methods that may be utilized to meet this requirement.  Some systems support multiple language messaging.  Software can be developed that recognizes the TTY tones and then treats them as a language variant.  Messages would then be delivered in TTY tones, much as some users might choose a language and receive messages in their preferred language.  One challenge with this approach is that many TTY callers do not make TTY tones until they see the call is answered with a “Hello GA” TTY message.  Therefore, they may not readily get connected to the TTY channel in a voice mail, auto attendant and interactive voice response system.  There are methods (as described in the next paragraph) for eliciting a response from the caller in TTY that could then be used to do the automatic switchover.  A second method is to provide a parallel system for TTY calls.  In this approach, a TTY call is identified, using the same greeting heard by non-TTY callers.  This may be done by an initial message that starts with a voice message, pauses, and ends with the greeting in TTY tones.  The hearing caller is invited, before the pause, to enter a key to enter the message tree.  After the pause and explanation to the hearing caller, the greeting message is repeated in TTY tones.  The hearing caller is thus routed to the audio messaging system and the TTY caller to the TTY messaging system.  This set-up would need to be designed to minimize delay in the sending of an initial TTY greeting or the TTY user will not be clear that they have called anything other than an exclusively voice based system. An acceptable third method would be to establish a separate number for TTY users with the TTY voice mail, auto attendant and interactive voice response system at that number. • What historic problems have there been? Attempts have been made with mixed results to record TTY tones in voice mail systems designed only for voice communications.  Care must be taken to assure that the quality in the digital circuitry is sufficient to faithfully record TTY calls. In addition, many TTY users prefer to use a telecommunications relay service to navigate a voice-based IVR system and type the information back to them.  This has resulted in significant delays and time-outs due to the need for the telecommunications relay service to inform the TTY caller of the choices and await the TTY caller’s response before entering the appropriate choices on their behalf.  [Also, see provision 1194.23 (d).]  The intention of this provision [1194.23 (c)] is to require voice mail, auto attendant, and interactive voice response systems to be directly usable by TTY users with their TTYs, without requiring the use of a telecommunications relay service.   • How do TTY users interact with systems that require DTMF tones? This provision requires voice mail, auto attendant and interactive voice response systems to be “usable” by TTYs.  Although it requires all spoken instructions to be available as TTY text, it does not specify which signals the TTY user will use to interact with the systems.  Some systems require a TTY response and other systems require a DTMF response (e.g., “touch tone” sounds).  Interactive voice response systems often require a user to enter DTMF tones to access a customer service line (e.g., enter their extension number) or to make menu selections.  In addition, telephone calling cards may require users to enter a personal identification number via DTMF.  Depending on the users’ equipment, these tones may be entered directly via a push button telephone or through the dialing system of a TTY.  Note that DTMF tones are not the same as TTY tones and TTYs only make DTMF tones when set in a “keyboard dialing” mode.  Also, not all TTYs can generate DTMF tones, so the ability to generate DTMF tones with the telephones is important.  Users with TTYs in the acoustic mode or with telephones connected in parallel with a direct connect TTY can enter DTMF tones directly from their telephone.  Vendors of TTY products can provide further information on how users may enter DTMF tones.  TTY accessibility does not impede the ability of a TTY user to enter DTMF tones, nor does it interfere with the ability of a voice mail, auto attendant, or interactive voice response system to receive DTMF tones.  Provision Requirements

  • Voice mail, auto attendant, and interactive voice response systems should be usable by TTY callers, both to leave and retrieve messages, as well as to use the system features.  This accessibility allows TTY users to navigate the systems independently without relying on a telecommunications relay service because the systems will directly send and receive TTY signals. 
  • Timing should be a consideration when designing the system to be “usable” as the provision requires.  TTY users need sufficient time to read and respond prior to the system timing-out.  Also, see 1194.23 (d).
  • Since the voice mail system of the agency should be completely TTY compatible, TTYs with answering machine functionality should not be needed (though the voice mail may or may not be easier to use), since TTY users could have their telephone answered by the central voice mail system like everyone else.

Recommended Practices

  • The TTY character error rate would ideally be no greater than that experienced by non-TTY users.  The benchmark used for wireless TTY compatibility is an average error rate no higher than 1%.
  • When a TTY accessible answering machine is used, instead of TTY accessible voice mail, only answering machines with high enough fidelity to accurately record and play back TTY tones should be used (i.e., many of the modern digital recorders would not work).  It is important that the machines also not mistake TTY tones for dial or other system tones and cut off recording of the TTY signals.  Designers should be clear that the availability of a TTY answering machine (assistive technology) is not considered a method of making a voice mail, auto attendant or interactive voice response system TTY-accessible.
  • It would be helpful if voice mail, auto attendant, and interactive voice response systems would either accept TTY Baudot tones or make it clear that the numbers that should be pressed are the ones on the telephone keypad (especially when they are talking to the user using Baudot). 
  • Read the IVR Accessibility Forum Disability Implications Matrix, which provides the industry with information about the barriers and advantages of IVR Systems for people with disabilities.  See: http://www.atis.org/atis/ivr/ivrhom.htm. The information is presented in three ways. The application view is by product or industry, the interface view shows each step required by a user, and the disability view shows interface implications for specific disability categories. All views include links to definitions in the IVR Forum’s Accessibility Glossary. Note that some recommendations listed go beyond what the 508 Standard requires.  

Time Interval Alerts [3]508 Provision §1194.23(d) Voice mail, messaging, auto-attendant, and interactive voice response telecommunications systems that require a response from a user within a time interval, shall give an alert when the time interval is about to run out, and shall provide sufficient time for the user to indicate more time is required. Introduction & Background When a system requires a user to respond within a specified time, some people with mobility or dexterity disabilities or those using TTYs where they must read the messages may have difficulty completing actions before the timeout.  TTY users may require extra time to interact with voice mail, messaging, auto attendant and interactive voice response systems.  For these users, limits on response time can present a real frustration and barrier to using such systems. Another class of users that often have problems with voice mail, messaging, auto attendant, and interactive voice response systems are TTY users of the Telecommunications Relay Service (TRS).  The TRS is a federally mandated system (Title IV of the ADA), which exists in all states, to primarily provide a translation function for TTY callers.  This process is slower than audio calls.  Voice mail, messaging, auto attendant and interactive voice response systems may timeout before the TTY caller can receive the system’s message in TTY code from the CA and type in their response.  In addition, when multiple choices are offered, TTY callers may need to clarify the options with the communication assistant before understanding their choices.  For TRS users, response time limits are a significant barrier.  This provision is also very pertinent to users of a type of relay service known as Speech to Speech (STS).  STS callers do not use TTYs.  STS callers have speech disabilities and use specially trained STS CAs to repeat what they are saying so that the other party can understand them.  Sometimes more than one attempt is necessary for the CA to understand what the person is saying before the CA can begin to pass the message on. Also, due to other physical disabilities, the STS user may also have difficulty entering DTMF tones in a timely fashion.  Designers are reminded that this timeout provision applies to all users of voice mail, messaging, auto attendant, and interactive voice response systems, not just TTY users.  For these reasons, this provision requires that the user be alerted when a time limit is approaching and that they be given the option for extending the time.  Ideally, users will have the option of overriding the timed response and be able to take as much time as required to enter their responses.  Alternately, users may continually be alerted to the timeout and extend it as long as they need, until they can effectively respond to the system as long as user’s input is not erased each time a time extension it evoked and granted. Design Guidance • Is my product affected by this provision? This provision applies to all voice mail, messaging, auto attendant, and interactive voice response systems that require a user response within a specified time interval. • After alerting the user, how much time should be allowed? It is desirable for an alert to be made 5 seconds before a response period times out, but a duration is not specified in the 508 standards.  The user should be given the option of indicating that additional time is needed to complete their response.  If additional time is requested, the information entered to the point of the warning announcement should be preserved and the user should be allowed to continue inputting information from that point. Provision Requirements

  • When a response time is used, the user should be alerted, as the end of the time interval is approaching, and be allowed to indicate that additional time is required. 
  • The alert should repeat at the end of each period until the user successfully completes the operation or purposely exits the function so that a destructive time-out does not occur.  This means that resetting the system in order to provide the user with another timed try (with no more time to complete it than the first time) is not sufficient to conform to the requirement of allowing the individual to indicate that more time is required. If the user requests additional time, it should be granted without erasing or otherwise affecting input given to that point.  For example, if the user is required to enter information, such as a social security number, the announcement and ensuing interaction should not erase the information input to that point.  The user should be able to request additional time and return to the input of information, as it stood when the warning announcement was issued.  The system should be designed to not erase input each time the individual resets or some users may tie up the system for extended periods of time as they repeatedly try to get all of their input into a single time-out cycle

Recommended Practices

  • Minimize the use of timed responses.
  • A minimum of 5 seconds could be given to the user to indicate that additional time is needed.
  • Some people with partial hearing loss only recognize some of the words in a message and may require that the message be repeated, repeated more loudly, or may simply require more time to comprehend what is being said.  Providing a way for users to repeat or slow down the message would be helpful.
  • Note that although not required under this provision, time-out warnings could be sent in the same sensory mode as the mode in which the conversation is transmitted. In fact, multiple sensory methods can be used to alert users that the end of a response period is approaching.  For example, an audible alert alone may not inform a user with a hearing disability that a time-out is about to occur, but a visual alert (on a display) could accompany the audible alert on a closed system.  If required for operation, such measures would be required under 1194.3 functional performance criteria.

 Caller ID and Similar Functions508 Provision §1194.23(e) Where provided, caller identification and similar telecommunications functions shall also be available for users of TTYs, and for users who cannot see displays. Introduction & Background This provision addresses two different problems: 1.) the accessibility of information which is normally presented on a display to users who cannot see displays; and 2.) the availability of information to TTY users that is usually provided on some landline digital telephone systems.  The second problem is an issue when TTY users do not use landline digital telephone systems, due to the potential for the system to corrupt TTY signals.  The kind of information pertinent to this provision is information about telecommunication functions.  Many current office and wireless telephones have displays that provide information such as Caller ID or indication of new voice mail messages to the user.  Caller ID, also known as ANI or automatic number identification, can display both the name and number of a caller.  Someone with a visual disability might not be able to see this information and therefore would not experience “comparable access” to the telephone system, unless that information was provided in another format.  TTY users may have special problems with obtaining this telecommunication information, which is commonly transmitted and displayed via digital trunks or lines on landline telephone systems.  TTY users have often been limited to the use of an analog line, which provided a connection point, supported ring signaling assistive technology, and avoided garbling of TTY through the digital telecommunications system. [See provisions 1194.23 (b) and (j).]   However, this analog bypass arrangement is not considered a method of 508-compliance because TTY users miss the functionality and additional information provided through a digital telephone system.  Therefore, this problem of TTY user information access needs to be addressed by design engineers in order for a telephone system to conform to the 508 standards.  Federal procurement officers should know that this is not a problem with all digital telephone systems. Design Guidance
•  Is my product and/or service affected by this provision? Products and/or services that deliver, support, or provide special information functions, such as Caller ID, are covered by this provision.  Automatic location identification (ALI), which displays a caller’s address, is also covered, but is less commonly used. •  How is accessibility to functionality information provided? Information about telecommunications functions can be made available visually, on a display, and audibly.  One method of meeting the provision through auditory access is commonly known as “talking Caller ID”.  Another way of meeting the provision is by providing compatibility with assistive technology.  For example, where telephones and computers are integrated, software can enable telecommunications information to be displayed via the computer screen.  This allows users to read it by using assistive technology, such as refreshable Braille displays or screen readers.  To elaborate, special functions, such as Caller ID, are often only available in digital form.  Many landline office telecommunications devices support the TAPI interface, which is a standard protocol allowing exchange of information between telecommunications equipment and information technology equipment, (i.e., telephones and computers).  There is a newer version of the TAPI protocol, known as the Extended TAPI protocol.  Through the Extended TAPI interface, the Caller ID number can be transmitted and viewed on a personal computer.  Software is available that will translate the information from the Extended TAPI protocol to a form usable by assistive software.  If the software is left running in the background, the user may access (audibly or tactilely using assistive technology) the telephone number of an incoming call in the same timeframe as someone looking at the telephone LCD display.  Thus, for situations where telephones and computers are integrated, the functionality of the computer could be used to meet this provision.  This is an example of “equivalent facilitation”.  A TAPI interface on a telephone not connected to a computer would probably not satisfy this provision unless the telephone had voice output of the visual information on its display. Provision Requirements

  • Products and/or services that deliver, support, or provide special information functions, such as Caller ID, in a visual mode should make the information available in at least one non-visual mode or make it available to assistive technology that will be present and that can display it in a non-visual mode.
  • Telecommunications function information, such as Caller ID, available to other users of the same system should be provided to TTY users of that system as well.

Recommended Practices

  • Most commonly, the non-visual format for presenting telecommunications information is audio.
  • Presenting telecommunications information through the integration of telecommunications equipment and information technology is one way of meeting this provision because it enables a user to attach assistive technology to access the telecommunications information. Currently, this method is only available on landline telephones.
  • When telecommunications function information is time sensitive, such as with a caller identification function, it could be made immediately available to the user without requiring user action to access.  As an example, the user would be able to have the callers’ identity announced immediately, if it is immediately displayed for other users.  This feature should be user selectable.

 Volume Control
508 Provision §1194.23(f)
For transmitted voice signals, telecommunications products shall provide a gain adjustable up to a minimum of 20 dB. For incremental volume control, at least one intermediate step of 12 dB of gain shall be provided. Introduction & Background People with hearing loss generally require additional volume to hear effectively.  A user may not be able to understand speech at nominal volume levels.  This provision enables people who are hard of hearing to increase their telephone volume gain in order to maximize their residual hearing.  Many people with hearing loss are more sensitive to noise and less able to recognize words in the presence of noise than individuals with normal hearing.  Therefore, increased volume assists these users in achieving a volume level and speech-to-noise ratio sufficient for their needs. Design Guidance
• Is my product affected by this provision? This provision applies to all telecommunications products that transmit a two-way voice signal.  Products that only provide one-way communications, such as speakers that give operating instructions to the user, are not covered by this provision.  • dB is a relative term, what is the reference quantity? The term dB is a logarithmic unit used to describe a ratio.  When used with SPL (e.g., 65 db SPL) it expresses an absolute measure of sound pressure level (against no sound).  Most telecommunications standards now define gain in terms of Receive Output Loudness Rating, not Sound Pressure Level. • What gain level is required? This provision requires products to be equipped with volume control that provides an This provision requires products to be equipped with volume control that provides amplification adjustable to a gain of at least 20 dB above the default volume..  If a volume adjustment is provided that allows a user to set the gain anywhere from 0 to the minimum requirement of 20 dB gain above default, then there is no need to specify an intermediate step of 12 dB.  If a stepped volume control is provided, one of the intermediate levels must provide 12 dB of gain above default. Some telephones are set with a higher default than others.  These telephones are not given “credit” for providing a high default setting and must still provide 20 dB of gain above their default setting in order to conform to this provision.  Some phones may allow the user to reset the default volume.  In these cases the default is that setting that the manufacturer normally uses for the telephones as sales time. Provision Requirements

  • The acoustic output should be controllable by the user.
  • For incremental volume control, at least one intermediate step of 12 dB of gain should be provided.
  • The maximum volume setting should reach at least 20 dB above the default volume setting.

Recommended Practices The intention of this requirement is that a usable signal be available at the maximum volume setting.  Commonly accepted frequency responses and distortion/clipping levels could be accomplished within acceptable range at maximum volume setting.


 Automatic Volume Reset
508 Provision §1194.23(g)
If the telecommunications product allows a user to adjust the receive volume, a function shall be provided to automatically reset the volume to the default level after every use.
Introduction & Background This provision applies to all telecommunications products that allow a user to adjust the volume. It was adopted from the ADA Accessibility Guidelines, where it applies to public telephones used by many people.  It also has roots in the FCC's Part 68 rule, which has required an automatic reset when a landline telephone is hung-up after a call in which the volume exceeds 18 dB gain.  The ability to override the reset is helpful to people with hearing loss who find it inconvenient to adjust their preferred amplification level for every call, especially on incoming calls.  In other words, the telephone will be loud every time they answer it. In December 2000, when the Access Board published the Section 508 standards in the Federal Register, it wrote in the preamble that allowing override of the reset function would require a waiver from the FCC.  However, since that time, the FCC did, in fact, issue such a waiver in March 2001. See the Public Notice at: http://ftp.fcc.gov/cgb/dro/vc_notic.doc.  And also see the  Memorandum Opinion and Order at:  http://ftp.fcc.gov/Bureaus/Common_Carrier/Orders/2001/da010578.doc.  Therefore, on this basis, the Access Board believes that a telecommunications product can conform to the Section 508 standards if it has either a fixed automatic reset function or an optional override of that switch.  This interpretation does not change the 508 standards, which still require an automatic reset function to be provided.  It simply acknowledges that a manufacturer (via the FCC waiver) has an option to enable users the ability to override the volume reset function, if the manufacturer wishes to design a telephone that way. It is important to draw attention to the word “function” in this provision.  There is a difference between requiring an automatic reset and requiring a function to automatically reset.  Requiring a reset after each call is a fixed action, whereas including reset as an option provides flexibility to turn that function switch on or off.  This 508 provision requires a automatic reset function, which is a broader requirement because it allows an override.  Provision 1194.23(g) does not preclude an override function.  For safety reasons, however, it is recommended that the reset function on telephones normally used by people who are hard of hearing be deactivated only when those telephones will not be shared with other people. The FCC granted its waiver on the basis that telephone manufacturers meet the following conditions:

(1) The volume reset override switch shall be labeled as such and located on the telephone in such a way as to not be accessible to accidental engagement; (2) A bright indicator light shall be prominently displayed on the front of the telephone and shall light up when the override is engaged and the telephone is placed in an off-hook condition; (3) Next to the light shall be a warning that the amplification is at a high level; (4) A caution on the use of the volume reset override switch shall be included in the users’ manual; and (5) The telephone shall include a warning printed in Braille that can be securely attached to the back of the handset, or, if the telephone has only a headset, above the dial buttons, to indicate that a high volume setting may be engaged.

Design Guidance
•  Is my product affected by this provision? This provision applies to all telecommunications products that allow the user to adjust the volume.  It has roots in the FCC's Part 68 rule, which requires an automatic reset when a landline telephone is hung up if the volume exceeds 18 dB gain.  This reset provision is a safety feature for handsets implemented by the FCC, and does not apply when a product is in hands-free [speakerphone] mode.  Provision Requirements
If a telecommunications product allows a user to adjust the receive volume, a function shall be provided to automatically reset the volume to the default level after every use.  Recommended Practices

  • A function may be provided that allows a user to override the automatic reset.
  • Phones that permit and override of automatic volume reset should comply with the terms in the FCC Report and Order discussed above.
  • The default level could be set anywhere by manufacturer or users within the acceptable ranges described in the appropriate standards. 
  • A visual indicator of volume setting that can be read prior to picking up the handset can be provided.  This is especially important in telephones that use the push of a button to increase volume via software internal to the telephone. This display design contrasts with telephones, which use dials, slides or other mechanical volume controls that can be easily viewed.

 Hearing Aid Compatibility 508 Provision §1194.23(h) Where a telecommunications product delivers output by an audio transducer which is normally held up to the ear, a means for effective magnetic wireless coupling to hearing technologies shall be provided. Introduction & Background There are several different ways in which hearing aid wearers use the telephone.  Some use the microphone on their hearing aid to pick up sound from the telephone speaker (acoustic coupling).  Some others use a hard-wired electrical connection between the telephone and the hearing aid (direct audio input, or DAI).  A sizeable minority of hearing aid wearers (typically but not exclusively those with higher degrees of hearing loss) use the telecoil feature found in many hearing aids to pick up the speech (inductive coupling).  The term “hearing aid compatibility” (HAC) as used in this section refers to inductive coupling, or telecoil compatibility. There are several problems that hearing aid users contend with that lead them to choose inductive coupling.  One is acoustic feedback, also known as whistling or squealing.  This is caused when the telephone speaker is held against the part of the hearing aid case with the microphone.  Two other problems are that the speech signal is weakened as it passes across the distance between the telephone speaker and the hearing aid microphone, and ambient noise may enter the hearing aid along with the speech. The solution to these problems for many people is to completely bypass the microphone and change to the telecoil “T” setting on their hearing aid (colloquially called the “telephone switch”).  The input to the hearing aid will be through a magnetic field surrounding the telephone handset.  This magnetic field is emitted from the telephone handset and will contain the speech of the other party.  The telecoil, a coiled wire inside the hearing aid, picks up the magnetic signal.  This is what is meant by hearing aid compatibility (HAC).   HAC is common in telephones due to the Hearing Aid Compatibility Act of 1988, which requires HAC in all essential wireline telephones.  That requirement is simply carried over to section 508.   This provision is important because some people with severe hearing loss are only able to use the telephone if they couple the hearing aid inductively to the telephone.  It should not be assumed that a person who is hard-of-hearing will hear effectively with volume control alone. It is noteworthy that some cochlear implants (the new ear level style) also have a telecoil incorporated in them.  Previously, cochlear implant users could plug their speech processors into an adapter on landline telephones for direct listening.  However, the inductive coupling method allows them to effectively use telecommunications products in a wireless fashion. Design Guidance • Is my product affected by this provision? This provision applies to telecommunications products that deliver an audio output to a transducer normally held to the ear.  Therefore, if the product is a fax machine, and does not have a handset, this provision is not applicable. This provision most commonly applies to telephone handsets, but applies to telephone headsets as well.  Telephone “headsets” go over the ear, and should not be confused with earphones that go inside the ear. • What is a T-coil and how does it work? A T-coil is a small inductive receiver element located in a hearing aid.  It is activated either manually using a small switch located on the hearing aid or by using a remote control supplied with some hearing aids.  By using a T-coil, a hearing aid can receive the magnetic field, and receive or demodulate the telephone speech from the signal.  The advantage of receiving the speech signal as a magnetic signal rather than an acoustic one is that there is no acoustic feedback or background noise to deal with.  This feature has made the T-coil option very popular with some hearing aid users.  An estimated 20% of hearing aids in the U. S. are ordered with a T-coil option.  (The use of T-coils has widened to other applications.  Some theaters and auditoriums have installed transmission loops, allowing T-coil users in the audience to receive the performance or presentation through a magnetic signal.  Portable assistive listening systems have also been developed that transmit discussions and lectures from a microphone directly to an attendee’s T-coil via a receiver with a magnetic coupler.) • What standards are used in determining compliance with this provision? With developments in technology, new kinds of speaker elements had been introduced.  Some of these speaker elements produced far lower or even no magnetic signal.  This effectively ended the ability to use a T-coil in those products.  Because of this, in 1988, the Hearing Aid Compatibility Act was passed requiring all wireline and cordless telephones to provide a magnetic signal sufficient to support the use of a T-coil.  The FCC enforces this industry requirement in Part 68 of its rules.  In its rules, the FCC adopted EIA RS-504 as the technical requirements for hearing aid compatibility.  Currently, there is no FCC requirement and no industry standard specifically concerned with defining HAC for wireless telephones.  Nevertheless, this section 508 provision covers both wireless telephones as well as wireline telephones. Provision Requirements Telecommunications products used for listening (that deliver output by an audio transducer that is held up to the ear) should emit a magnetic field sufficient for effective inductive coupling with hearing technologies, such as hearing aids and cochlear implants equipped with t-coils. Recommended Practices

  • The signal provided could be within the useful range prescribed by the applicable industry standards in order to assure good reception with the wide variety of hearing aids.
  • Wireline telephones could comply with the requirements of FCC Part 68.316 (EIA RS-504).

 Minimized Interference508 Provision §1194.23(i)Interference to hearing technologies (including hearing aids, cochlear implants, and assistive listening devices) shall be reduced to the lowes Arial">t possible level that allows a user of hearing technologies to utilize the telecommunications product.Introduction & Background The purpose of this provision is to help ensure that users of hearing technologies are not prevented from using telecommunications products due to interference.  The term “hearing technologies” includes hearing aids, cochlear implants, assistive listening devices, and other types of hearing technologies.  These technologies pick up radio frequency (RF) signals, which are radiated from digital wireless/cellular telephones’ antennas using energy pulses that the hearing instrument circuitry picks up and demodulates as audible interference.  In addition, magnetic fields generated by handset components, such as battery leads, may cause noise when hearing technology wearers are using the telecoil to couple inductively to the handset.  Many hearing technology wearers, therefore, hear significant buzzing or pounding sounds that may completely mask the speech of a call and make the wireless digital telephone unusable for voice conversations.  Some hearing technologies are more immune to interference than others.  Some digital wireless/cellular telecommunications transmission technologies cause more annoying interference than others. Compatibility ideally means that the hearing instrument and telecommunications product function well as a system.  That may require meeting both the magnetic coupling requirement [provision (h)] as well as this minimized interference requirement [provision (i)].  Previously in the 1980s when the Federal Communications Commission (FCC) referred to hearing aid compatibility (HAC), it meant only magnetic coupling [provision (h)]. That was written during a period in time when wireless/cellular telephones were analog and most of those telephones did not cause interference.   However, in keeping with the new challenges posed by digital technologies, the FCC recently redefined HAC for digital wireless/cellular telephones to mean a combination of both magnetic coupling and minimized interference. This portion of technical assistance will address only the minimized interference issue. Compatibility, in this limited context, refers to the coordination of hearing technologies with RF immunity and wireless devices that minimize RF emissions. The hearing technology industry and cellular telephone industry recently completed a standard, ANSI C63.19-2001, which provides specific tests and target parameters for hearing aids and wireless/cellular telephones.  This measurement methodology was developed to facilitate improved interoperability between hearing aids and some wireless/cellular telephones through the implementation of the standard by both industries.  Design Guidance
• Is my product affected by this provision? This requirement is applicable to all products that provide a voice telecommunications function.  • What guidance can be used in conforming to this provision? In August 2003, the Federal Communications Commission (FCC) issued a ruling directing wireless/cellular telephone manufacturers and wireless/cellular service providers to take steps to reduce the amount of interference caused by wireless/cellular telephone handsets.  The FCC’s Report and Order is intended to ensure that redesigned compatible cellular telephone handsets will be widely available and hearing aid immunity will continue to improve. Specifically, it requires a percentage of wireless/cellular digital telephones with reduced interference within 3 years.  To view this FCC Report and Order, see: http://ftp.fcc.gov/cgb/consumerfacts/accessiblewireless.html.  ANSI C63.19-2001 provides procedures to measure electromagnetic emissions produced by wireless/cellular handsets.  The standard provides two summary test results, one for radio frequency emissions that create a buzzing noise in hearing aids primarily when they are in the microphone (default) setting, and one for compatibility with the hearing aid's telecoil.  For each of these results, there are four levels defined, with 4 being the best (lowes Arial">t emission) category.   The FCC has set a minimum of category 3 for telephones that are to be considered (and labeled) as compatible with hearing aids. (The FCC rule begins to go into effect in 2005.)  The FCC's rule thus includes consideration of interference when determining whether a wireless/cellular telephone is "hearing aid compatible. Code Division Multiple Access (CDMA) based technologies generally cause less bothersome interference in hearing aids than do Global System for Mobile Communications (GSM) technologies.  In light of the FCC ruling, the Federal Interagency Committee on Disability Research (ICDR) held a timely “Summit on Interference to Hearing Technologies” in September 2003.  Participants included representatives from the digital wireless telephone and hearing technologies industries, disability organizations, research centers, and Federal agencies, such as the FCC and the Food and Drug Administration (FDA).  Presentations were made on laws that address hearing aid compatibility, new technological developments, and telephone designs that reduce interference, and the results of laboratory and consumer testing.  Proceedings from the conference will be posted on ICDR’s website at www.icdr.us. Provision Requirements

  • Reduce interference to hearing technologies to the lowes Arial">t possible level that allows a user of hearing technologies to utilize telecommunications products, while at the same time maintaining desired performance of those telecommunications products.

Recommended Practices

  • Consider applying methodologies outlined in ANSI C63.19 to inform the product design process. ANSI C63.19-2001 may be used to help attain the lowest level of RF emissions from digital wireless/cellular telecommunications handsets.  The Alliance for Telecommunications Industry Solutions (www.atis.org) is currently (2003) determining whether revisions to the standard will be recommended to the standards body.
  • Apply information learned from the ICDR Summit on interference (discussed above).
  • Some techniques to consider when trying to reduce interference emissions from digital wireless telephones are:
  • Positioning the antenna away from the ear area.
  • Reducing power.
  • Modifying the antenna to reduce RF currents in the area near the user’s ear.
  • Using a clamshell design that moves the antenna away and partially shields it.
  • Providing the user with ability to turn off backlighting.
  • Inserting shielding in the wireless/cellular digital telephone.
  • Replacing an omni-directional antenna with a directional antenna.
  • Study the effects of cordless (landline) telephone products on hearing technologies and ameliorate interference. Digital cordless phones have been reported to interfere with some hearing aids.  Specifically, vendors could test products and report on the extent to which they result in interference to hearing technologies when the cochlear implant or hearing aid is in microphone mode, and when it is in telecoil mode.

 Transmission/Conducting Information508 Provision §1194.23(j) Products that transmit or conduct information or communication, shall pass through cross-manufacturer, non-proprietary, industry-standard codes, translation protocols, formats or other information necessary to provide the information or communication in a usable format.  Technologies which use encoding, signal compression, format transformation, or similar techniques shall not remove information needed for access or shall restore it upon delivery. Introduction & Background Services such as closed captioning and video description provide access to multimedia transmission for people with disabilities.  The information that is communicated in these services includes text, audio, and coded information for delivery and/or display of the information.  This provision was created largely in response to problems with transmission of closed captioning information without distortion or removal of the captions.  It also applies to TTY tones – although those are also covered specifically in another provision as well.  For example, captions are sometimes stripped out of the signal, or characters are lost in compression or enhancement activities during transmission, unless safeguards are taken.  Captions are also sometimes scrambled when frames are lost in transmission or when frames are removed from video material to make the program shorter.  Sometimes the captions are inadvertently removed when new synch tracks are laid down when duplication of video occurs, so that the uncaptioned version is erroneously transmitted. This provision applies to systems that transmit video content that may contain captioning information or video description.  It would also apply to any other devices that transmit information or encode information for transmission (and decodes it after). This provision also clearly applies to TTY signals passed through office telecommunications products and services.  TTYs were designed to function as modems over standard telephone lines.  Some technological changes in telecommunications systems have caused problems for the TTY signals.  Another example of TTY problems with digital service is in wireless (e.g., cellular) communications.  In some systems, frame errors occur at levels that are tolerated well for voice communications, but are very disruptive to TTY communication.  Other problems have arisen from some noise cancellation algorithms in codecs and from some implementations of digital signaling and audio signal compression schemes.  However, the wireless industry, under order from the FCC to make services compatible with TTYs, has now completed its work (in collaboration with handset and TTY manufacturers).  Wireless carriers have reported to the FCC that their services carry TTY signals intact. This provision is written broadly so as to cover future telecommunications services that may impact accessibility.   Captioning, video description, and TTY products that meet the criterion of “cross-manufacturer, non-proprietary, industry-standard” should be supported. Design Guidance• Is my product affected by this provision? This provision applies to products that transmit or conduct information or communications that may contain coding necessary for accessibility.  For example, a video broadcast could contain closed captions.  This provision also applies to other telecommunication products, such as routers, that deliver, audio, video, and TTY signals. • What kinds of captioning problems is this provision addressing? Historical sources of problems have been stripping and garbling or loss of synchronization of caption data due to compression, duplication, transmission, frame loss, re-encoding, or digital rights management methods. Some systems completely remove captioning accidentally during transmission or compression simply because the designers are not aware that it exists in the synchronization periods of the signal.  On other systems, compression techniques may corrupt the captions since the compression techniques were designed without knowledge of or consideration for captions.  Still other systems, to save bandwidth, do not deliver secondary or auxiliary channels that carry accessibility information.  Thus, the captioning or video description information is effectively blocked and the users who rely on these services for accessibility are denied their benefit. Provision Requirements

  • Products that transmit or conduct information or communication, should pass through cross-manufacturer, non-proprietary, industry-standard codes, translation protocols, formats or other information necessary to provide the information or communication in a usable format. 
  • Technologies which use encoding, signal compression, format transformation, or similar techniques should not remove information needed for access or should restore it upon delivery.

Recommended Practices Federal procurement officials need to understand that each product in the transmission path must be examined for compliance with this provision.  The overall telecommunications system (both services and hardware) must be selected to ensure that valid signals will not be corrupted along the way to the user.


 Controls & Keys[4]508 Provision §1194.23(k) Products which have mechanically operated controls or keys, shall comply with the following:

(1) Controls and keys shall be tactilely discernible without activating the controls or keys. (2) Controls and keys shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. The force required to activate controls and keys shall be 5 lbs. (22.2 N) maximum. (3) If key repeat is supported, the delay before repeat shall be adjustable to at least 2 seconds. Key repeat rate shall be adjustable to 2 seconds per character. (4) The status of all locking or toggle controls or keys shall be visually discernible, and discernible either through touch or sound.

Introduction & Background These provisions apply to user operable controls, which are components of a product that are operated by physical contact.  Typically, the control panel or user interface, and their major components, buttons, keys, and knobs, are the primary items of concern.  However, mechanically operated controls such as latches are also covered – as long as they require contact for “normal operation”.  Examples of normal operation would include selecting features and pressing keys.  Operable controls required for maintenance, service, repair, installation, and configuration or occasional monitoring are not covered by this provision.  An example would be an RJ-11 plug that may be connected into a jack only one time. Since section “k” contains 4 provisions, each of those provisions will be addressed separately within this area. Each provision will have its own Requirements and Recommendations sections. Provision 1194.23(k)(1) Controls and keys shall be tactilely discernible without activating the controls or keys. Design GuidanceWhat is meant by 'tactilely discernible'? Individual keys should be locatable and distinguishable from the product surface and adjacent keys by touch. Conformance with this provision can be accomplished by using various shapes, spacing, or tactile markings.  The normal desktop computer keyboard, for example, would meet this provision because the tactile marks on the "j" and "f" keys permit a user to locate all other keys tactilely from these landmarks and the edges of the keyboard.  In addition, the physical spacing of the function, "num pad" and cursor keys make them easy to locate by touch.  Many telephones also have a raised dot on the number 5 button, enabling them to orient their fingers around the 12 keys. Because touch is necessary to discern tactile features, this provision requires keyboards to allow exploration by touch that will not automatically activate a function based on mere contact.  Fortunately, most keyboards require some pressure on individual keys in order to enable a keystroke. However, "capacitance" keyboards would not meet this provision because they react as soon as they are touched and have no raised marks or actual keys.  They may not react at all when touched by a person with a prosthesis.  A "membrane" keypad with keys that must be pressed can be made tactilely discernible by separating keys with raised ridges so that individual keys can be distinguished by touch. How are touch screens and other contact sensitive controls dealt with? This provision only applies to products that have mechanically operated controls or keys, such as standard telephone keypads and computer keyboards.  It is not intended to apply to touch screens.  Touch screens and other contact sensitive controls are not specifically prohibited by any of the provisions of 1194.23.   However, since all devices need to meet 1194.31, the performance criteria, products that incorporate touchscreens or contact sensitive controls are only able to meet the 1194.31 criteria if an alternative way of operating them using tactilely discernable controls was provided.   At this time, some telecommunications products with touch screens and other contact sensitive controls do not conform with this provision.  For example, there are PDAs with telephone functionality and touch screens, as well as desk telephones with touch screen enhanced features that cannot be operated via tactile controls. Provision Requirements Controls and keys should be tactilely discernible without activating the controls or keys. Recommended Practices

  • Consider placing tactile marks on top of the keys, not beside them, and raising the marks a minimum of 0.5 mm.
  • On telephone keypads, the “5” key could have a tactile marker, such as a “nib” or “bar”, on the top surface of it.
  • On QWERTY keyboards, the “F” and “J” keys could have a raised bar on them.
  • Recessed keys or keys with concave tops can be an aid to users operating them with a mouth stick or head stick.  Raised keys aid users with visual disabilities to locate keys.
  • To help people with fine motor control problems, a key guard or overlay option could be provided when practical.
  • Making other important keys tactilely distinct (shape, size, spacing, tactile markings) can make them easier to remember and find.

Provision 1194.23(k)(2) Controls and keys shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. The force required to activate controls and keys shall be 5 lbs. (22.2 N) maximum. Design Guidance • How will individuals with disabilities benefit from the requirement enabling operability without tight grasping, pinching, twisting or pressure? Individuals with tremor, cerebral palsy, or other disabilities may have difficulty operating systems which require fine motor control, a steady hand, or two hands to be used simultaneously for operation.  Individuals with high spinal cord injuries, arthritis, and other conditions may have difficulty operating controls which require significant strength. The provision limits the force required to five pounds and is based on section 4.27.4 of the ADA Accessibility Guidelines.  This provision is also consistent with the Telecommunications Act Accessibility Guidelines. • How are these requirements applied to controls that must be turned? The provision specifically states that keys and controls shall not require twisting. However this does not mean that rotary knobs cannot be used.  If the knobs can be operated within the 22.2 N force limit and without requiring the user to twist, pinch or tightly grasp, then they would conform.  Many knobs which have a reasonable surface coefficient of friction and which turn without great effort would meet the requirements of this provision.  It is important to keep in mind that sufficient room should be provided around the knobs if they are to be operated in this fashion (e.g., with the side of the hand). Provision Requirements

  • Controls and keys should be operable with one hand.
  • Controls and keys should not require tight grasping.
  • Controls and keys should not require tight pinching.
  • Controls and keys should not require tight twisting of the wrist.
  • The force required to activate controls and keys should be 5 lbs. (22.2 N) maximum.

Recommended Practices

  • Just as simultaneous two-handed operation is prohibited, multiple fingers, and simultaneous operations of all types should be avoided and are prohibited by 1194.31e which prohibits simultaneous actions and applies to all products.
  • Using controls and latches which require light pressure to operate, such as push buttons, up/down control buttons, instead of side to side control buttons, concave rocker switches, or sliding controls would make it easier for users with different types of physical disabilities.
  • It is recommended to avoid using controls that must be held down for a period of time if the period exceeds 5 seconds and there is no other way to achieve the function.

Provision 1194.23(k)(3) If key repeat is supported, the delay before repeat shall be adjustable to at least 2 seconds. Key repeat rate shall be adjustable to 2 seconds per character. Design Guidance • What does "key repeat" mean? This provision addresses a challenge encountered by some people without fine motor coordination.  Sometimes they accidentally don’t release a key fast enough and get several (auto-repeated) characters when they only intended to type 1 (because the key repeat was faster than they can move).   This could potentially result in the same character displaying several times on the screen.  It could also result in the same function repeating (e.g., causing the telephone volume to get too high.) Some systems do not support key repeat. However, when key repeat is supported and you can make adjustments, you may adjust the length of time the key can be held down before it starts repeating.  You also can adjust the time delay between repeats. • Is my product affected by this provision? The “key repeat” requirement only applies to controls that have a “key repeat” function.  Most telephone products would not have a repeat function on the dial pad.  However, many telephones have key repeat functionality on menu navigation arrows, backspaces or volume controls.  Telephony functions on products with a keyboard may also have other repeat functions. Provision Requirements If key repeat is supported, the delay before repeat should be adjustable to at least 2 seconds.  Key repeat rate should be adjustable to 2 seconds per character. Recommended Practices

  • It is recommended that an option be provided to disable the key repeat function.
  • It is recommended that an option be provided to set a key acceptance rate (how long the key must be depressed before being recognized).
  • It is recommended that if the intention of repeating a key is to reach a target goal, then an alternate way of entering that target be provided.  For example, if a person were to increase volume from 1 to 20 by depressing a key 20 times, it would be easier to simply (or alternatively) press the numbers 2 and 0 to enter 20.

Provision 1194.23(k)(4) The status of all locking or toggle controls or keys shall be visually discernible, and discernible either through touch or sound. Design Guidance • What is meant by "status of controls" and why do people need that information? This provision requires the status of toggle controls, such as the "caps lock" or "scroll lock" keys, such as those found on computer keyboards, to be identifiable by either touch or sound, in addition to visual means.  For example, adding audio patterns, such as ascending and descending pitch tones that indicate when a control is turned on or off, would alleviate the problem of a person who is blind inadvertently pressing the locking or toggle controls.  Also, buttons which remain depressed when activated and switches with distinct positions may meet this provision. Provision Requirements The status of all locking or toggle controls or keys should be visually discernible, and discernible either through touch or sound. Recommended Practices

  • Using two different types of feedback, such as a combination of tactile, audible, and visual feedback helps make products easier for people with sensory disabilities to use.
  • When using audio feedback, consider associating intuitively meaningful sounds with actions.  For example, try using increasingly high-pitched sounds with increasing amplitude.  Use cascading sounds with rotary or slide controls with the pitch associated with the change in control.
  • Audio indication of a toggle status, instead of being a continuous signal, could be sufficiently long to alert the user to the position of the toggle switch. 

III.  REFERENCES ANSI C63.19-2001, “American National Standard for Methods of Measurement of Compatibility between Wireless Communications Devices and Hearing Aids”. EIA RS-504-1983, "Magnetic Field Intensity Criteria for Telephone Compatibility with Hearing Aids. TIA/EIA 825-A (2003), “A Frequency Shift Keyed Modem For Use On The Public Switched Telephone Network” TIA TSB-121, “2.5 mm Audio Interface For Mobile Wireless Handsets - Text Telephones (TTY)”


NOTES

[1] 36 CFR 1194, Electronic and Information Technology Accessibility Standards, Architectural and Transportation Barriers Compliance Board, Published in the Federal Register on December 21, 2000.
[2] Americans with Disabilities Act, 42 U.S.C. §§ 12101 et seq., (ADA).


[3] The 508 provisions, §1194.22(p) and §1194.25(b), are identical or have substantial overlap with this provision.  The guidance provided for those sections may provide additional insight on this requirement.
The provisions contained in §1194.25(c), §1194.26(a) and §1194.26(b) are identical or have substantial overlap with this provision.  The guidance provide for those sections may provide additional insight on this requirement.[4] The provisions contained in §1194.25(c), §1194.26(a) and §1194.26(b) are identical or have substantial overlap with this provision.  The guidance provide for those sections may provide additional insight on this requirement.