More than one sense, more than one support
Media mostly reaches people through two senses: sight and hearing. A sensory impairment affects one of them, or sometimes both, and the effects can range from mild to complete. The result is that no single accessibility feature serves everyone. Subtitles carry spoken words to people who cannot rely on hearing. Audio description carries pictures to people who cannot rely on sight. Sign language serves people whose first language is signed. Each fills a gap the others leave open.
This article looks at how these supports relate, especially for viewers whose needs combine or overlap. It is general information, and the right mix for any individual should come from that person.
What each support does
Subtitles and captions. Text of speech, and in captions also of important sounds. They help people who cannot hear or understand audio. They depend on the viewer being able to see and read the screen.
Audio description. An added narration that describes important visual details, such as actions, settings and facial expressions, in gaps between dialogue. It helps people who cannot see the picture or cannot see it well. It depends on the viewer being able to hear.
Sign language. Either an interpreter shown on screen or a program made in a sign language. It serves people who use sign as a first or preferred language, for whom written text in a spoken language may be less natural than signing.
Transcripts. A text document of the speech, with sound and visual description added. A transcript can be read by a screen reader, shown through a braille display or enlarged, so it is flexible across needs.
Where the supports interact
The supports are not independent, and combining them takes some thought.
- Screen space. Subtitles, a sign language interpreter window and other on-screen elements all compete for space. Placement should avoid hiding the interpreter or covering key visuals.
- Audio space. Audio description must fit in pauses in the dialogue, so heavy speech leaves little room. Likewise, a soundtrack mixed with description must remain clear.
- Overlapping information. A viewer who uses both subtitles and audio description gets the same dialogue through reading and the same visuals through narration. Mixed needs should not mean information overload, so the volume of text and sound should stay manageable.
- Timing. If captions run late, they can clash with description or with a signed version running in parallel.
Seen from the viewer’s side, the goal is to be able to turn each layer on or off and, where possible, adjust it.
Partial and combined impairments
Not all sensory impairments are total. Many people have low vision or partial hearing, and some use a mix of aids. A low-vision viewer might read large, high-contrast subtitles, while a different one prefers audio. A person with hearing loss and some sight may rely mainly on captions. Someone with both losses, which calls for deafblind access, may need text delivered through touch. The key is that the specific form of an impairment matters far more than the label.
Aging often brings gradual changes in both sight and hearing together, so many older viewers have mild combined needs. For them, clear, large captions and good sound can both matter. This overlaps with the experience of older viewers.
Cognitive and physical needs too
Some viewers have sensory impairments along with other disabilities, and each can change what works. Someone who is both hard of hearing and dyslexic, for example, may find captions helpful but tiring. A person with limited hand control might find it hard to change settings through a small menu. Voice control, simple remote controls and sensible defaults all play a part, which is why device settings should be easy to reach.
Planning for several needs
For people who make or publish media, the practical question is what to provide. A reasonable approach, used by many organizations, is to start with a base layer and build up.
- Good audio and clear visuals. Plain speech, not overwhelmed by music, and information not conveyed by color or sound alone.
- Accurate captions as a standard option, delivered as a separate track so viewers can restyle them.
- A transcript, ideally including visual description.
- Audio description for content in which visuals carry meaning that is not spoken.
- Sign language where a community strongly relies on it, such as for public information.
Building accessible production into the process from the start is cheaper and more effective than adding it at the end. What is required in law and what is recommended differ from place to place, and a qualified professional or the relevant authority can say which applies.
Testing with real people
Technical checks only go so far. Viewers who use these supports can quickly tell whether subtitles are cluttered, whether description fits, or whether a transcript works with their device. Gathering feedback from the people involved and acting on it is the most reliable way to find out. Even a small group of testers can reveal problems that a checklist would miss.
The takeaway
Sensory access is a matter of layers and choice. Subtitles are a strong layer for those who cannot hear, but they are one of several, and their value is greatest when they sit comfortably alongside the others.