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    Harpers Ferry Center

Accessibility & Audiovisual Media


Captions display spoken dialogue as printed words on television screens, computer monitors, projection screens, caption boards and other visual displays. Captions are specifically designed for viewers with hearing loss to enable their full participation when viewing video or multimedia productions. They include information regarding on- and off-screen sound effects such as music or laughter. Captions also hold secondary benefits for people who are learning a foreign language, learning how to read, or watching TV in a noisy area, as well as those who understand best by processing visual information.

What is the difference between open and closed captions?

Open captions are displayed automatically as part of the video, without having to be selected by the user.

Closed captions normally do not appear on screen unless the viewer has selected them to appear. The person viewing the presentation must be using technology that includes a closed caption decoder. The decoder will allow the otherwise-hidden data within the television signal to be displayed on the user’s TV screen or computer monitor. Many newer television models allow viewers to toggle captions on or off with ease.

What is the difference between captions and subtitles?

Subtitles are used to translate dialogue into a different language. They are primarily intended for hearing audiences, while captions are primarily intended for people with hearing loss. Subtitles rarely convey nonverbal sounds such as music or sound effects, whereas captions identify speakers and sound effects using text such as a "phone ringing" or "footsteps," and use symbols to indicate other sounds such as music.

Captions are typically displayed on-screen as white letters within a black box. Subtitles are generally not displayed within a black box and do not have standardized font requirements.

What is a caption board?

A caption board is an LED screen that displays the captions. It is a separate piece of equipment placed underneath, above, or beside the projection screen or video monitor. Caption boards come in a variety of sizes. The correct size is determined by the size of the room, the size of the screen and the distance between audience and screen. Some caption boards have built-in decoders, while others require a separate decoder.

Many older theater installations utilize caption boards. However, the January 31, 2008 DOI Directive requires new programs to display captions (or Subtitles for the Deaf and Hard of Hearing) on screen at all times. This directive guarantees that the program is in compliance at all times, and reduces the cost of equipment and time spent troubleshooting and replacing equipment in the future.

Why do I have to display captions at all times?

Captions help us reach an even wider audience—from visitors with very moderate hearing loss to visitors who cannot hear at all. Always displayed, captions also automatically assist visitors who would otherwise not ask for this accessibility feature. Visitors requiring this assistance will therefore not have to ask, and park personnel will not have to be trained to turn captions on and off upon request.

Audio Description

What is audio description?

Audio description describes the visual content of video or multimedia programs. It provides individuals who are visually impaired with information that further describes the visual content not provided in the primary audio track. Audio description is a separate audio track synchronized with the program’s primary audio track. An audio description narrator describes actions, gestures, scene changes, and other visual information. The narrator also describes titles, speaker names, and other text that may appear on the screen. Audio description should be carefully scripted and is best produced by trained professionals.

Does everyone have to hear the audio description if it is selected?

No. The audio description is recorded on a separate audio track and is not heard over the main loudspeaker(s). Visitors requesting audio description will typically receive a headset and receiver. The audio description track is then transmitted to the headset via a radio frequency or infrared signal. Only those with headsets will hear the audio description track.

Assistive Listening

What is assistive listening?

Assistive listening utilizes various devices that amplify volume for individuals who have mild to profound hearing loss and may or may not use a hearing aid. Assistive listening devices (ALDs) include headsets, earbuds and induction loops. The amplified sound is transmitted via radio frequency, infrared, or induction loops to the user’s headset, earbuds or hearing aid.


Audio Description for tv, video, and film

Assistive Listening Systems

Closed Captioning (CC)

Top to bottom: Access symbols for Audio Description, Assistive Listening Systems, and Closed Captioning. Courtesy National Disability Arts Forum.

If I have captions, why do I need assistive listening devices?

Many people simply need additional assistance in order to hear. Some individuals may not be able to read, or may not be able to read at the level necessary to fully comprehend captions, such as young children. Both the Architectural Barriers Act and Section 508 of the Rehabilitation Act require the use and compliance with assistive listening technology and devices.

How much will it cost to add captions, audio description, and assistive listening to my existing programs?

Unfortunately, there is no cookie-cutter price for production, equipment, and installation of these accessibility requirements, particularly for existing programs. Factors to consider include the length of the program, the presentation format, and the type of AV equipment currently installed. For this initiative, Harpers Ferry Center has developed some basic cost-estimating tools than can be used to generate Class C estimates. It is recommended that you contact Harpers Ferry Center as soon as possible to request an estimate.

What kind of equipment maintenance is necessary, and will I have to budget for yearly purchases such as new batteries?

Like your existing equipment, this equipment will also be subject to basic maintenance. Specific maintenance for accessibility equipment includes the replacement of foam headset or earbud covers after each use and cleaning of plastic headset or earbud devices. Batteries for audio description/assistive listening receivers will also need to be recharged or replaced periodically.

If I currently have a show in production, should I assume that it will be captioned and audio described?

No! Whether your show is being produced by Harpers Ferry Center or by an independent contractor, please verify that your program will be captioned and audio described and that assistive listening devices are available to visitors.

What is a “program number” and where can I find this information to fill out the Accessibility Upgrade Information form?

Harpers Ferry Center assigns a discreet program number to each audiovisual product we produce. Programs produced independently of Harpers Ferry Center may not have an assigned HFC program number. Look on your program master, such as the DVD, for an identifying number that looks like “TV-####” or “AS-####.”

Does this memo only apply to theater films? What about my exhibit videos, audio stations, computer interactives, etc.?

The October 20, 2006 Director’s Memo applies to all audiovisual programs. If you are unsure whether your program falls under this initiative, please ask. If Harpers Ferry Center cannot answer your question, they will refer you to someone who can. Your park and regional accessibility coordinators are also good resources to go to with questions. Even if some of your programs fall outside of this initiative, PMIS statements can still be written to ensure that you are meeting all accessibility regulations within your park.

My show is old and outdated. Can I simply request the production of a new program?

Possibly, but you should discuss your request with your region to ensure that you will be meeting the needs of this initiative. However, if a new show cannot be produced by the Director’s deadline of December 31, 2007, and you plan to continue showing your existing program, then you still need to make your existing program accessible.

What is the first step I need to take to seek assistance with accessibility requirements?

Harpers Ferry Center can work with you to evaluate your initial accessibility needs. For this initiative, we require that you complete an Accessibility Upgrade Information Form Microsoft Word Document that includes detailed information about your current program(s) and equipment. This will enable HFC to provide you with a Class C estimate for your PMIS statement.

Who can I contact for further information or assistance?

For further assistance from Harpers Ferry Center, please call 304-535-5050.

How do I let visitors know that these accessibility features are available?

Providing clearly visible signage publicizing accessibility at your park is critical. The universal signs for closed captions, assistive listening, etc. may be found on the Map Symbols & Patterns for NPS Maps website and should be placed in clearly visible areas at your visitor center and elsewhere within the park. You can also publicize your accessibility features on your website and in park publications such as newsletters and site bulletins.

Well-trained staff is the other crucial component of accessibility. All staff should be familiar with accessibility requirements and the equipment used to fulfill these requirements. They should be able to locate, operate and maintain the equipment, and to assist visitors who request assistance.

Related Links

Section 508: Video and Multimedia Products

Audio-Visual Accessibility Initiative for Visitors with Disabilities PDF

National Center on Accessibility

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