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Accessing Interactive Television: It's More than Meets the Eye

Tom Wlodkowski
Project Manager, Access to Convergent Media Project
CPB/WGBH National Center for Accessible Media
WGBH Educational Foundation
125 Western Ave.
Boston, MA 02134
voice: 617 300-3486
fax: 617 300-1035
E-mail: tom_wlodkowski@wgbh.org


The onset of digital television - with its capability to deliver multiple programs and interactive services simultaneously - will cause the most significant change to this medium since its launch in 1939. Imagine accessing streaming data about a candidate for President while watching the final in a series of presidential debates a week before the election. If steps are not taken now to address accessibility, the potential exists that people with disabilities will loose ground in gaining access to all that the information age has to offer.

This paper highlights existing roadblocks preventing individuals who are blind or visually impaired from effectively using convergent media technologies such as a digital cable set-top box (STB) or stand-alone digital television receiver. Solutions to improve usability of these technologies are also discussed. This work is a product of the CPB/WGBH National Center for Accessible Media (NCAM) Access to Convergent Media Project.


Convergent media" refers to the growing body of programming and services arising from the intersection of broadcast and cable television, enhanced/advanced/digital television, computers, and Internet technology. The evolution of digital television and other broadband technologies will change the way people access current information. While convergence technologies will open many new doors, the potential exists that these technologies will close as many doors for individuals who are blind or visually impaired if steps are not taken to ensure some alternate means of navigation in this graphic-rich environment.

The old paradigm of passive television viewing is rapidly fading. Soon television will deliver an array of interactive educational, civic, commercial, and entertainment services to the homes, classrooms, workplaces, and communities of all Americans. Television itself will be changing. In the analog world, broadcasters are limited to one program stream. In the digital world, up to four program sources can be aired simultaneously. In order to make a selection from the wide array of available programs and services, the user will be required to interact with a graphics-rich electronic program guide (EPG). The EPG is an integral component in digital set-top boxes and over-the-air digital television receivers.

The Access to Convergent Media Project is focusing on the set-top box and the electronic program guide for several reasons: 1) the STB is currently the most affordable option to access convergent media, 2) cable STBs, due to their reliance on wires to send and receive data, will offer more interactive services than terrestrial systems and 3) many solutions developed for the EPG are likely to enable blind users to successfully interact with other services delivered through the set-top box such as e-commerce, web browsing, program enhancements, and other interactive features.

A Viewer's Experience

The profile below broadly paints what NCAM envisions as an effective alternate user interface for an electronic program guide. NCAM has developed a prototype audio-enabled EPG based on this profile, Project staff will use this presentation to demonstrate the prototype in order to generate feedback on our approach from consumers and experts in the field of assistive technology. The prototype will ultimately be used to demonstrate conventions for designing a universally accessible EPG to broadcasters, cable and direct broadcast satellite providers and consumer electronics manufacturers.

It's 10 p.m. and Joe, who is blind, wants to watch television. Joe's wife and son, both of whom are sighted, are not available to read the local program guide. Even if they were available, Joe thrives on being independent and doesn't want to rely on his family to access this information. Sure, he could surf channel by channel and wait at each stop to figure out by program audio what the current program is. That is exactly what he and other blind viewers have had to do for years because the traditional program guide was purely visual. And in the 200+ channel universe, Joe would spend all of his time surfing rather than enjoying a specific program. But now Joe is no longer forced to surf aimlessly, thanks to the enhanced services available through his new digital set-top box (STB). Joe's cable company offers an STB that can communicate the information displayed on the screen via spoken audio. For the first time, the electronic program guide (EPG) is accessible.

When Joe turns on his television, he discovers that the access features on the STB have been turned off. Upon pressing the menu key on the remote control, a voice prompts him to "select a configuration." The assistive audio also mentions how to select from the list of stored STB configurations. Joe selects Audio Navigation, which puts the STB in a mode designed to allow blind users to successfully interact with it. Because Joe is an experienced user of voice navigation, his previously stored personal configuration includes a setting to drive the speech synthesizer in fast mode, to minimize the time it takes to read text. (His mother, who is also blind, needs the audio to be slower, so her configuration indicates a slow listening speed.)

Now the STB presents the main menu where a list of available choices is read aloud. Using the STB remote control, Joe steps through the menu and selects the EPG. Once inside the EPG, the audio presents several options for interaction with EPG content - Search, Read from current time (10 p.m.) forward, Read by date, etc. Joe selects the current time option.

If a sighted user selected this option without the access features enabled, they would be presented with a multi-column display. The screen may have channels in a vertical column on the left, a timeline (10:00, 10:30, etc.) across the top, and next to the channel column, a second vertical column with program information for each channel. If the audio output simply read this display, Joe would hear information out of context. With this in mind, the accessibility mode acquires the data and presents it in linear format. The audio reads:

10 p.m. (brief pause)
Channel 2---CNN Larry King Live
Channel 3---FOX Baseball: Red Sox vs. Yankees
Channel 4--- ... (and so on)

Joe can interrupt the sequence at any time by simply hitting the arrow keys on the remote. With no interruption by the user, the STB continues reading linearly until the list of offerings is complete, wrapping from 10:00 to 10:30 to 11:00, etc. A single down arrow interrupts the audio output, and puts the STB into a suspended state. A single down arrow would now read the next channel entry, wherever the EPG was interrupted. Two down arrows in quick succession moves to the next time slot (10:30, the next major table discontinuity). Three down arrows in quick succession repositions to the next date, etc. After a slight pause, the voice continues announcing the list of offerings available at that date, time, and channel.

[Note: this type of navigation is friendlier to all types of users, not just blind users, since it allows the user to minimize unnecessary data presentation during navigation.]

Joe decides to watch the Red Sox and interrupts the audio by clicking the Enter key on the STB remote when channel 3 is announced. After a while, Joe decides to watch another program. This time he decides to search the EPG for a specific program type. Joe is a musician and is curious if there are any music related offerings. He enters the EPG, and selects "Search" from the opening screen. The STB announces a list of program genres. Using the STB remote, he steps through the list and selects Music. Once the search results are in place, Joe is presented with the same choices as before -- Read from current time (now 11 p.m.) forward, Read by date, etc. Read from Current Time Forward is selected and the audio begins, first announcing the time, then reading the channel and corresponding program information. Joe is intrigued by a documentary on Charlie Parker airing on A&E. Wanting more information on this program, he highlights the program and double-clicks the "enter" key on the remote. In this mode, Joe hears a detailed description of the program. He decides to watch the program, and disables the EPG by clicking Enter for that selection, A&E, Channel 33, on the EPG.

Key Components

Several components are necessary in order for an Electronic Program Guide (EPG) delivered via a digital set-top box to be accessible to a blind or visually impaired user:

Support of multiple user configurations

At it's highest level, the STB must be modal, allowing users to easily toggle between the default "visual" mode and "access" mode, the latter of which causes the STB to present data in a non-visual manner (most likely audio). This type of support will ensure the STB meets the needs of all members of the household.

Accessible navigation Scheme

Blind users must be able to step item by item through a menu of choices to make a selection. The highlighted item must be announced. Since virtually all current EPGs use the up, down, left and right arrow keys on the remote control to step through the list of available programs and services, this scheme should work for blind or visually impaired users assuming the item that has focus is announced. The active menu item should also have visual focus in order to improve usability by low vision users. One solution to illustrate visual focus is to draw a box around the active item. Additionally, consistent shortcuts programmed into the use of the few navigational buttons can greatly enhance the usability of the remote for all users. A shortcut like double-clicking to indicate movement through major table sub-headings is a helpful navigation tool for blind and sighted viewers alike.

Assistive audio
Implementation of assistive audio may be accomplished through any combination of synthetic and digitized speech. The speech component could be stored locally on the STB, or stored on a cable "headend" server and loaded into the STB RAM as needed. Whichever source type/delivery method is used, some audio native to the STB will likely be required. This will insure that a blind user has support for invoking the access features, from simply turning accessibility features on, to selecting amongst multiple user configurations which are customized to each of the several members of a household.

When playing assistive audio, it is important for the STB to temporarily fade or completely interrupt the conventional program audio, so that the assistive audio can be clearly heard and understood. Additionally, the ability to adjust the rate and verbosity of the assistive audio can greatly enhance the usability of this feature.

Presentation logic
In addition to providing assistive audio, the accessibility mode needs to get at the underlying data of the EPG and render it in a user-friendly manner. Simply announcing existing on-screen textual information is not always the best way to make that information accessible. For example, while a table format may be the most efficient use of screen space for presenting program guide content for sighted users, blind users benefit from a linearized presentation. When thinking about audio presentation of information, the software designer must endeavor to forget the "look" of the data, and concentrate on the "feel" of the data.

Additional Efforts

NCAM through its DTV Access Project is also looking at accessibility issues concerning the transmission and reception of digital television content. The main focus of the DTV Access Project is to encourage implementation of advanced closed captioning and video description services in professional and consumer digital television systems. the Project has created test materials, authored standards and guidelines and participated in recent FCC rulemakings in support of these services. With funding from the Corporation for Public Broadcasting, the project also assists the nation's public television stations in maintaining and enhancing captioning and description services as they transition from analog to digital broadcast facilities. A brief overview of the DTV Access project will be provided at the conclusion of this presentation.

Funding for NCAM's DTV Access and Access to Convergent Media projects is provided by the National Institute on Disability and Rehabilitation Research (NIDRR), U.S. Department of Education.

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