Perception - hearing, feeling and seeing

Introduction

Some people need to convert content from one form to another to perceive it. For example, someone who is deaf-blind requires audio and visual content in a tactile form (such as Braille). Other people need to perceive content through multiple senses, such as someone with dyslexia who may need to hear and see the text to understand it better.

Content in textual form can be more easily converted into other forms and is therefore particularly useful. However, text-only content poses barriers for many people who have difficulty with written language. Graphics and illustrations can be made accessible and often improve understandability, ease-of-use, and satisfaction with websites and applications for everyone.

In some cases, content can be converted into different forms using software or hardware. For example, a text-to-speech software can convert text into speech. In other cases, content authors need to provide alternative forms of the content. For example, at least some level of human intervention is necessary to create textual descriptions for images and captions for audio content. Sometimes software tools, such as speech and picture recognition, can assist authors in providing such alternatives but the conversion is usually not fully automatable.

Examples of accessibility features

• Audio descriptions – (also referred to as “video descriptions” and “described video”) narrations that describe important visual details in a video. These narrations can be during natural pauses in the audio, or in separate audio files or audio tracks in multimedia.
• Auditory, tactile, and visual notifications - prompting or alerting the user in different ways such as by blinking or displaying visual dialogs, by using sound, or by vibration.
• Braille – a system using six to eight raised dots in various patterns, to represent letters and numbers. These characters are read by scanning over the raised dots using the fingertips. Braille is used by people who are blind but not all individuals who are blind know braille.
• Captions – text with a verbatim recording of any speech and with descriptions of relevant auditory information that appears simultaneously with the audio (including audio that accompanies video in multimedia). For real-time captioning typically professional CART writers are necessary.
• Sign language – a visual form of communication that is primarily used by people who are deaf. It involves hand, body, and facial expressions to transmit words, phrase, and tone. For instance, the intensity of a gesture could indicate the mood or emphasis of particular information. As in written languages, there are many sign languages and dialects, some of which are recognized as official languages in some countries. Not all people who have auditory disabilities or who are deaf know sign language.
• Symbols – icons that represent words or concepts used instead of text by some people with impaired communication, including people with difficulties reading or writing.
• Text-to-speech (sometimes called “speech synthesis” or “speech output”) - automatic conversion of text into a synthesized voice reading the text aloud.
• Transcripts – text manuscripts containing the correct sequence of verbatim recording of any speech, and descriptions of important auditory or visual information.

Examples of assistive technologies and adaptive strategies

• Refreshable Braille display – a mechanical terminal that displays a line of Braille characters (usually 40-80) by raising and lowering the dots (pins) dynamically. Braille devices with capabilities of small computers incorporate Braille displays. These devices can be used to take notes, calculate numbers, or to interface with other devices such as public information kiosks.
• Screen reader – software that processes content on the desktop and in web browsers, and converts it to others forms such as text-to-speech and Braille. Screen readers typically provide other functions such as shortcut keys, different modes for processing content and interacting with it, and the ability to highlight the text that is being read aloud.
• Voice browser – similar to screen reader but usually only processes web content. Voice browsers are typically not developed as assistive tools but as alternative web browsers for mobile devices or similar.

Stories related to perception

• Martine, older adult student who is hard of hearing
• Ilya, senior staff member who is blind
• Preety, middle school student with Attention Deficit Hyperactivity Disorder and Dyslexia
• Noor, teenager who is deaf and blind