Glossary

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E-Ink Display(also: Electronic Ink, E-Paper, Electronic Paper Display)

A display technology that mimics the appearance of ink on paper by using electrically charged particles to create images. E-ink displays are characterized by high readability in direct light, minimal glare, extremely low power consumption, and reduced eye strain compared to…

E-Tran Frame(also: Eye-Transfer Frame, Eye-Pointing Frame, ETRAN)

A low-technology augmentative and alternative communication (AAC) device consisting of a transparent frame or board that allows a person to communicate by directing their eye gaze toward symbols, letters, words, or colour-coded groups arranged on the frame. The communication…

E-textiles(also: Electronic Textiles, Smart Textiles)

E-textiles are textile objects that integrate electronic components such as sensors, lights, or actuators into their design. They combine traditional textile techniques (sewing, embroidery, weaving) with electronic circuitry, often using conductive yarn or thread to create…

EMG Switch(also: Electromyography Switch, Muscle Signal Switch)

An assistive technology switch that detects electrical signals produced by muscle contractions (electromyography) to generate a switch activation. EMG switches can detect even very small muscle movements, such as a slight facial twitch or jaw clench, making them suitable for…

EVITA(also: Enabling Visually Impaired Table Access)

A specialized table browser developed at the University of Manchester designed to enable visually impaired users to navigate, browse, and read HTML data tables non-visually in a manner analogous to how sighted readers interact with tables in print. EVITA provides keyboard-based…

Ear-EEG(also: Around-the-Ear EEG, cEEGrid)

Ear-EEG refers to electroencephalography (EEG) recorded using electrodes placed in and around the ear canal rather than on the scalp. Consumer-grade ear-EEG devices such as cEEGrid sensors are unobtrusive, easy to wear without hair preparation, and suitable for everyday…

Earcon(also: Auditory icon)

A brief, distinctive sound used in a user interface to convey information, status, or feedback non-visually. Earcons serve a similar function to visual icons but through the auditory channel. In accessible interfaces, earcons can augment or replace visual cues — for example, a…

Echolocation(also: Human echolocation, Active echolocation)

The ability to determine the location and characteristics of objects by emitting sounds and interpreting their echoes. While commonly associated with bats and dolphins, many blind and low-vision individuals develop echolocation skills for spatial navigation, using self-generated…

Edge enhancement(also: Edge detection, Contour enhancement)

An image processing technique that identifies and highlights the boundaries between objects in a visual scene, typically rendering them as bright lines against a dark background or overlaying them on the original image. For people with low vision, edge enhancement can make…

EdgeWrite(also: Edge Write)

A gestural text entry method that uses the physical edges and corners of a square input area to guide character formation. Unlike traditional handwriting recognition that analyzes the full path of a stroke, EdgeWrite recognizes characters based on the sequence of corners hit,…

Educational Technology(also: EdTech, Learning Technology, Instructional Technology)

The use of technological tools and resources to facilitate teaching and learning. In accessibility contexts, educational technology encompasses assistive tools designed to support students with disabilities, such as screen readers, refreshable Braille displays, auditory graphing…

Eigenfaces

A computer vision technique for face recognition that uses Principal Component Analysis to represent faces as a linear combination of standardized face components (eigenvectors derived from a training set of face images). Developed by Turk and Pentland in 1991, Eigenfaces was…

Eight-Dot Braille(also: 8-Dot Braille, Computer Braille)

An extended braille system that adds two additional dots below the standard six-dot braille cell, creating a 2x4 matrix of eight dots that can represent 256 unique characters (compared to 64 in standard 6-dot braille). Eight-dot braille is primarily used with refreshable braille…

Electrical Muscle Stimulation(also: EMS, Neuromuscular Electrical Stimulation, NMES)

A technique that uses electrical impulses delivered through surface electrodes to elicit muscle contractions. EMS is used therapeutically for muscle re-education, spasticity management, and rehabilitation, and has been explored in HCI as an output modality — for example, guiding…

Electroencephalography(also: EEG)

A non-invasive method of recording electrical activity of the brain using electrodes placed on the scalp. In assistive technology, EEG is the primary sensing technology behind brain-computer interfaces (BCIs), which allow people with severe motor impairments such as paralysis or…

Electroencephalography(also: EEG)

A non-invasive method of recording electrical activity in the brain using electrodes placed on the scalp. EEG is fundamental to most consumer and research brain-computer interfaces because it is relatively inexpensive, portable, and safe compared to invasive neural recording…

Electrolarynx(also: Artificial Larynx, Electronic Larynx)

A handheld, battery-powered device that produces voice for people who have lost their larynx. The device is held against the neck or cheek and generates vibrations that travel through the throat tissues into the oral cavity, where the user shapes the vibration into speech using…

Electrolarynx(also: Artificial Larynx, Electric Larynx, EL Device)

A handheld battery-powered device that produces mechanical vibrations to generate speech for people who have lost their larynx (voice box), typically due to laryngeal cancer surgery. The device is held against the neck or cheek, where it transmits vibrations through the tissue…

Electromagnetic Actuation(also: EM Actuation)

A method of producing physical movement using electromagnetic fields generated by electric coils. In accessibility contexts, electromagnetic actuation is used to move tactile elements — such as magnetic markers or braille pins — to create dynamic tactile displays and interfaces…

Electromagnetic Tracking(also: Magnetic Tracking, 6-DOF Tracking)

Electromagnetic tracking is a position and orientation sensing technology that uses electromagnetic fields to determine the location and rotation of a sensor in three-dimensional space. Systems like the Polhemus tracker generate a low-frequency magnetic field from a stationary…

Electromyography(also: EMG, Electromyogram)

Electromyography (EMG) is a technique for measuring the electrical activity produced by muscles when they contract or are at rest. In accessibility and assistive technology, EMG sensors placed on the skin can detect muscle activations even when there is no visible movement,…

Electronic Assistive Technology(also: EAT, Electronic AT)

Computer-based devices and systems that enable people with severe disabilities to perform tasks they would otherwise be unable to accomplish, including communication, environmental control, mobility, and computer access. Electronic assistive technologies are often integrated…

Electronic Travel Aid(also: ETA)

An electronic device designed to help blind or visually impaired people navigate their environment by detecting obstacles and conveying spatial information through non-visual feedback such as audio cues, vibrations, or tactile signals. Electronic travel aids range from simple…

Electrooculogram(also: EOG, Electrooculography)

The electrooculogram (EOG) is a technique for measuring the electrical potential difference between the front and back of the eye using surface electrodes placed around the eyes. This corneal-retinal potential (CRP) varies linearly with eye rotation along both horizontal and…

Electropalatography(also: EPG, Dynamic Palatography, Palatography)

A technique for recording tongue-palate contact during speech using an artificial palate fitted with electrodes. When the tongue touches the palate, it completes a low-amperage electrical circuit that is detected and displayed visually in real time. In accessibility and deaf…

Electrotactile Feedback(also: Electrotactile, Electrical Tactile Stimulation)

A form of haptic feedback that uses controlled electrical current applied directly to the skin or through a thin insulating layer to generate tactile sensations. Unlike vibrotactile feedback (which uses mechanical vibration) or pressure feedback (which uses physical force),…

Emacspeak(also: The Emacspeak Audio Desktop)

A free, open-source speech output system built on top of the Emacs text editor that provides complete auditory access to a computing environment for blind and visually impaired users. Created by T. V. Raman in 1994 and still actively maintained, Emacspeak pioneered the concept…

Embodied Conversational Agent(also: ECA, Virtual Agent, Animated Agent)

A computer-generated animated character designed to interact with human users using multiple simultaneous communication channels — typically speech, eye gaze, facial expression, head and body posture, and hand gestures. ECAs are used in tutoring systems, customer-service agents,…

Embossed Braille(also: Hard Copy Braille, Paper Braille)

Braille text produced by physically raising dots on paper or other materials, creating a tactile surface that can be read by touch. Embossed Braille is produced using Braille embossers (printers), slates and styluses, or Braille typewriters such as the Perkins Brailler. It…

Embossed Graphics(also: Embossed Tactile Graphics, Raised Graphics)

Tactile graphics produced by a braille embosser or similar device that creates raised dots and lines on heavy paper or card stock. Embossed graphics are one of the most common methods for producing tactile representations of visual information for blind and visually impaired…

Embossed Paper(also: Raised Paper, Tactile Paper)

Paper that has been processed to create raised textures, shapes, or text that can be perceived through touch. In accessibility contexts, embossed paper is used to represent visual information non-visually, including diagrams, user interface layouts, maps, and graphical elements.…

Embosser(also: Braille Embosser, Tactile Graphics Embosser)

A device that creates raised (embossed) output on paper or other materials, used to produce braille text and tactile graphics for people who are blind or have low vision. Braille embossers function similarly to printers but press dots upward into heavy paper to create tactile…

Embossing(also: Braille Embossing, Tactile Embossing)

The process of creating raised patterns on paper or other materials by pressing from behind, producing content that can be read by touch. In accessibility, embossing is the primary method for producing Braille text and tactile graphics. Braille embossers are specialized printers…

Emergent Communicator(also: Beginning Communicator, Pre-Symbolic Communicator)

A person who is in the early stages of learning to use symbolic communication — understanding that symbols, words, pictures, or signs can represent objects, actions, and concepts. Emergent communicators may use a combination of gestures, vocalizations, facial expressions, and…

Emotional Agency

The ability of an individual to independently manage their emotional responses and experiences, particularly when encountering sensitive or personal information. In the context of accessibility and generative AI, emotional agency refers to the capacity of blind and low vision…

Emotional Design

A framework developed by Don Norman describing how people evaluate and form attachments to products through three cognitive levels: visceral (immediate sensory and aesthetic responses), behavioral (functional performance and usability), and reflective (personal meaning,…

Empathy Lab(also: Accessibility Lab, Assistive Technology Lab, AT Lab)

A dedicated physical or virtual space where designers, developers, and other team members can experience digital products using assistive technologies and simulations of various disabilities. Empathy labs typically include screen readers, switch devices, eye-tracking systems,…

End Effector(also: Haptic Stylus, Haptic Pen)

The physical component of a haptic device that the user directly touches or manipulates to interact with a virtual environment. In assistive technology contexts, end effectors translate digital information into tactile sensations — the device applies forces, vibrations, or…

End-User Programming(also: EUP, End-User Development, EUD)

A design approach that enables people without formal programming training to create, modify, or combine software behaviors to suit their own needs. Typical end-user programming systems expose computational building blocks through accessible interfaces such as visual block…

Energy Conservation(also: Energy management)

Energy conservation refers to a set of self-management strategies designed to help people with chronic conditions, fatigue-related disabilities, or fluctuating energy levels maintain function and independence by using their available energy efficiently. Core techniques include…

Engagement Detection(also: Engagement Monitoring, Engagement Recognition)

The use of sensors, computer vision, or other technologies to automatically assess whether a person is actively engaged with a task, device, or activity. Engagement detection systems typically monitor observable behaviours such as gaze direction, touch interaction patterns,…

Enhanced Activities of Daily Living(also: EADLs, EADL (gerontology), Advanced Activities of Daily Living)

In gerontology and human-robot interaction research, the highest tier of everyday activities — higher-order social, recreational, and civic pursuits that enable full participation in society, such as using computers and the internet, volunteering, engaging in hobbies, pursuing…

Enhanced Area Touch(also: Area Touch, Expanded Touch Area)

A touchscreen interaction technique that enlarges the effective touch point from a single pixel to a larger circular area, expanding both the motor space (the physical area the user needs to target) and the visual space (the on-screen representation of targets). When multiple…

Environmental Awareness(also: Situational Awareness, Environmental Sound Awareness)

The perception and understanding of what is happening in one's physical surroundings, particularly through auditory cues. For Deaf and hard of hearing individuals, environmental awareness is often reduced because many everyday signals — appliance timers, doorbells, approaching…

Environmental Control(also: Environmental Control Unit, ECU, Smart Home Control)

Technology that enables people with severe physical disabilities to independently control aspects of their environment such as lights, doors, temperature, televisions, phones, and other electronic devices. Environmental control systems can be operated through various access…

Environmental Control System(also: ECS, Electronic Aids to Daily Living, EADL)

An environmental control system (ECS) is an assistive technology that enables people with physical disabilities to independently control devices and features in their environment, such as lights, doors, televisions, phones, and computers. ECS devices accept input through various…

Envision AI(also: Envision)

An AI-powered visual assistance technology available as a smartphone app and as smart glasses that provides scene descriptions, text reading, and object identification for blind and low vision users. Envision uses computer vision and large language models to describe visual…

Equalization(also: EQ, Audio Equalization, Adaptive Equalization)

The process of adjusting the balance of frequency components in an audio signal by boosting or attenuating specific frequency bands. In accessibility contexts, adaptive equalization can be used to compensate for background noise by selectively boosting frequencies that are being…

Ergonomic Keyboard(also: Ergonomic Input Device)

A keyboard designed to reduce physical stress, strain, and injury risk during typing by conforming to the natural posture and biomechanics of the hands, wrists, and arms. Ergonomic keyboard designs include split keyboards (angled halves to reduce ulnar deviation), tented…

Event-Related Potential(also: ERP)

An event-related potential (ERP) is a measured brain response that is the direct result of a specific sensory, cognitive, or motor event. ERPs are extracted from electroencephalography (EEG) recordings by averaging brain signals time-locked to repeated presentations of a…