Glossary

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AI Suitcase(also: AI-suitcase, Accessibility AI Suitcase)

A suitcase-shaped autonomous navigation robot for blind and low-vision travellers, developed as an open research platform by IBM Research, Carnegie Mellon University, Miraikan (the Japanese National Museum of Emerging Science and Innovation), and project partners. The user holds…

Accessible Pedestrian Signal(also: APS, Audible Pedestrian Signal, Talking Traffic Signal)

A traffic control device that communicates pedestrian signal information in non-visual formats, typically through audible tones, speech messages, or vibrating surfaces, enabling blind and visually impaired pedestrians to know when it is safe to cross a street and in which…

Acoustic Vehicle Alerting System(also: AVAS, Minimum sound requirement, Pedestrian warning sound)

A class of vehicle systems that emit artificial sound to alert pedestrians and other road users to the presence and movement of quiet vehicles — typically electric and hybrid vehicles at low speeds, where tire and aerodynamic noise are insufficient for detection. Regulatory…

Age-Related Vision Loss(also: Age-Related Visual Impairment)

Vision impairment that occurs as a consequence of aging, representing the most common cause of blindness and low vision worldwide. Conditions include age-related macular degeneration, glaucoma, diabetic retinopathy, and cataracts. The prevalence of significant visual impairment…

Ambient Audio(also: Ambient Sound, Environmental Audio, Background Audio)

The background sound of an environment — voices, traffic, water, wind, music, birdsong — captured incidentally rather than as the main focus of a recording. In accessible photography and audiophotography tools, ambient audio is often recorded automatically in the seconds leading…

Anticipatory Grasp(also: Pregrasp Planning, Pre-grasp, Pre-shaping)

Anticipatory grasp refers to the pre-shaping of the hand before contact with an object, based on expectations about the object's size, shape, and orientation. In sighted people this planning is driven primarily by visual input during the reach phase and produces smooth,…

AppleVis

A community-driven website and discussion forum dedicated to accessibility on Apple platforms (macOS, iOS, iPadOS, tvOS, watchOS) for blind and low-vision users. It hosts app directories, podcasts, tutorials, and peer-support discussions focused on VoiceOver and related…

Assistive Suitcase(also: Robotic Suitcase, Smart Suitcase)

A mobility aid in the form factor of a rolling travel suitcase that has been augmented with sensors, computing, and feedback mechanisms to help blind or low-vision travellers navigate public spaces. The suitcase form factor is appealing because it is socially unobtrusive in…

Audio-Based Interface(also: Audio Interface, Auditory Interface)

A computer interface that uses sound as the primary means of conveying information and supporting interaction, rather than visual display. Audio-based interfaces are essential for blind and visually impaired users and may employ speech output, environmental sounds, musical…

Audio-Based Navigation(also: Audio Navigation, Auditory Navigation)

A navigation approach that uses audio output — typically synthesised speech, spatial audio cues, or sonification — as the primary means of providing wayfinding information to users. Audio-based navigation systems are particularly important for blind and visually impaired people,…

Audiophotography(also: Audiophotograph, Audio Photograph, Sound Photograph)

A medium proposed by Frohlich and Tallyn in which a photograph is packaged together with an associated audio recording — typically ambient sound captured at the moment of the shutter, a spoken caption added afterwards, or both. For accessibility practice the audiophotograph is a…

Aural Eavesdropping(also: Audio Eavesdropping, Auditory Shoulder Surfing)

A security attack in which an unauthorized person overhears sensitive information such as passwords, PINs, or personal data being spoken aloud. This is a particular concern for people who are blind or have low vision because screen readers announce all on-screen content audibly,…

BVI(also: Blind and Visually Impaired, BLV, Blind and Low Vision)

A widely used abbreviation in accessibility and HCI research denoting "blind and visually impaired" — the inclusive category that covers people who are totally blind, legally blind, or have any form of low vision. Closely related variants include BLV ("blind and low vision"),…

Bixby Vision

Bixby Vision is a visual-assistance feature in Samsung's Bixby assistant, built into Samsung Galaxy phones, that uses the device camera and AI to describe scenes, read text, identify objects and currency, translate signs, and answer questions about the live camera view. For…

Blind and Visually Impaired(also: BVI, Blind and low vision, BLV)

An umbrella term used in accessibility research and practice to encompass people whose vision is significantly reduced, from partial low vision (for example, reduced acuity, contrast sensitivity, or field of view) through total blindness. The term includes people who are…

BlindSquare

A GPS-based iOS accessibility app designed for people who are blind or have low vision, providing spoken information about the surrounding environment — nearby points of interest, intersections, street names, and compass direction — drawn from OpenStreetMap and Foursquare data.…

Bone-Conducting Headphones(also: Bone Conduction Headphones, Bone Conduction Headset)

Headphones that transmit sound by vibrating the skull bones directly to the inner ear, bypassing the outer and middle ear and leaving the ear canals open. In accessibility contexts they are widely used by blind travellers and wayfinding systems because the wearer can continue to…

Bone-Conduction Headset(also: Bone-conduction headphones, Bone-conduction earphones)

A headphone that delivers sound by vibrating the bones of the skull and jaw rather than projecting air through the ear canal, leaving the wearer's ears uncovered and able to hear ambient sound. Bone-conduction headsets are widely used in blind and low-vision navigation contexts…

Browsing Fatigue(also: Navigation Fatigue, Screen Reader Fatigue)

Physical and cognitive exhaustion experienced by users — particularly screen reader users and those with motor impairments — when navigating web content through repetitive, effortful interactions. For blind screen reader users, browsing fatigue results from excessive keyboard…

CaBot(also: Carry-on Robot, Carnegie Mellon Suitcase Robot)

A research project begun in 2017 at Carnegie Mellon University that developed a suitcase-shaped autonomous navigation robot to guide blind and low-vision travellers through indoor public spaces. CaBot pioneered the "grip-the-handle-and-walk" interaction pattern, combining LiDAR,…

Cane Simulation(also: Virtual Cane, White Cane Simulation)

A virtual reality application that simulates the experience of using a white cane (long cane) for navigation, allowing blind users to explore virtual environments through haptic feedback. In a cane simulation, the user's finger or hand position is mapped to a virtual cane that…

Cane Technique(also: White Cane Technique, Long Cane Technique)

The set of physical methods a blind or low-vision person uses to manipulate a long white cane while traveling. Common techniques include the two-point touch (side-to-side sweeping, touching ground at each step), constant-contact (sliding the cane tip along the ground in an arc),…

Category 3 Blindness(also: ICD-10 H54 Category 3, WHO Category 3 Visual Impairment)

A classification of severe visual impairment under the World Health Organization's ICD-10 coding for disorders of the visual system (H54). Category 3 covers blindness in which the better eye has presenting visual acuity worse than 1/60 (20/1200 Snellen) but can still perceive…

Clock Technique(also: Clock Method, Clock Face Direction System)

An orientation method used in mobility training for blind and visually impaired people in which directions are communicated using the positions on an analogue clock face. The user imagines standing at the centre of a clock with 12 o'clock directly ahead, 3 o'clock to the right,…

Cocktail Party Effect

The human ability to focus auditory attention on a single speaker or sound source while filtering out competing voices and background noise. Named after the experience of following one conversation at a noisy party, this perceptual phenomenon demonstrates that the auditory…

Congenital Blindness(also: Congenital Vision Loss)

Blindness or severe visual impairment present from birth or very early childhood, as opposed to acquired or adventitious blindness that develops later in life. The distinction is significant for accessibility because congenitally blind individuals may have different information…

Emergent Literacy(also: Early Literacy, Pre-literacy)

The developmental process through which young children (typically birth through age 5) acquire foundational skills and concepts about reading and writing before formal instruction begins. For sighted children, picture books and illustrations play a crucial role by providing…

Exercise Accessibility(also: Fitness Accessibility, Accessible Physical Activity)

The design of exercise environments, equipment, programs, and technologies to be usable by people with disabilities. Exercise accessibility encompasses both physical spaces (accessible gyms, adapted tracks, swimming pools with lifts) and the technologies and guidance systems…

EyeMusic

A visual-to-auditory sensory substitution device that converts images into sound, enabling people who are blind to perceive visual information including shape, location, and color. EyeMusic uses a left-to-right sweep algorithm where horizontal position maps to time, vertical…

Finger-Worn Camera(also: Ring camera, Finger-mounted camera, Finger assistive camera)

A miniature camera attached to a finger, typically via a ring or thimble-like housing, that captures images from the hand rather than from the head or chest. In accessibility contexts, finger-worn cameras enable blind and low-vision users to point and query objects through…

Fingertip Deflection

A haptic guidance technique in which a wearable device gently pulls or tilts the fingertip in a chosen direction (abduction, adduction, flexion, or extension) to bias arm motion toward a target during reach. Unlike vibrotactile alerts that must be symbolically decoded, fingertip…

Force Feedback Joystick(also: Haptic Joystick, Rumble Joystick)

An input device that combines a traditional joystick with motors or actuators that apply physical resistance, vibration, or directional forces to the user's hand, providing tactile information about the virtual environment being navigated. In accessibility applications, force…

Graphic Transcription(also: Image Transcription, Accessible Graphic Transcription)

The process of converting visual graphics (charts, maps, floor plans, diagrams) into formats accessible to blind and visually impaired users, such as tactile graphics, audio descriptions, or interactive multimodal representations using sonification and speech. Graphic…

Grasp Aperture(also: Hand Aperture, Finger Aperture)

Grasp aperture is the distance between the thumb and opposing finger(s) as the hand opens to receive an object during a reach. It scales with perceived object size, peaks before contact at a value typically larger than the object itself, and then closes to grip - a well-studied…

HULOP(also: Human-scale Localization Platform)

An open-source indoor navigation platform originally developed by IBM Research to support blind navigation using Bluetooth Low Energy (BLE) beacon fingerprinting for localisation plus a topological map server for route planning and point-of-interest data. HULOP has been used as…

Haptic Exploration(also: Tactile Exploration, Touch Exploration)

The process of acquiring spatial and object information through systematic touch and hand movements. Haptic exploration involves active manipulation and movement across surfaces to perceive shape, size, texture, temperature, and spatial relationships. For people who are blind or…

Haptic Glove(also: Data Glove, Tactile Glove, Wearable Haptic Device)

A wearable device worn on the hand that provides tactile feedback through vibration motors, piezoelectric actuators, pin arrays, or other mechanisms embedded in the fingers and palm. In accessibility research, haptic gloves have been explored for several applications: enabling…

Home Page Reader(also: IBM Home Page Reader, HPR)

A talking web browser developed by IBM Japan in the late 1990s, designed specifically for blind and low-vision users. Home Page Reader combined a web rendering engine with the ProTalker text-to-speech synthesiser and exposed navigation commands through the numeric keypad,…

Image Description App(also: Visual assistance app, AI visual description app)

A smartphone or wearable application that captures an image of the user's surroundings and returns a spoken or textual description of its content, aimed primarily at blind and low-vision users. Early crowdsourced systems such as VizWiz (2010) relied on remote human workers;…

Interpersonal Safety

Interpersonal safety refers to protection from threats of bodily harm caused by other people, such as assault, harassment, or violence. For people with disabilities, interpersonal safety presents distinct challenges because visual or auditory cues used to assess threats from…

JAWS for Windows(also: JFW)

JAWS (Job Access With Speech) for Windows is a commercial screen reader from Freedom Scientific (now Vispero) that provides speech and braille output for blind and low-vision users on the Windows operating system. The JFW mailing list and user group (jfw.groups.io) is one of the…

Landmark(also: Navigation Landmark, Environmental Landmark)

A distinctive environmental feature used as a reference point during navigation and wayfinding. In Orientation and Mobility training for people with visual impairments, landmarks are categorized by the sense used to detect them: structural landmarks (doors, stairs, elevators)…

Last Meter Problem(also: Last Mile Problem, Final Approach Problem)

In assistive technology for blind users, the challenge of bridging the gap between knowing an object exists and physically reaching or interacting with it. While object detection apps can identify what objects are present and approximately where they are, they typically cannot…

Last-Few-Meters Problem(also: Last 10 Meters Problem, Last Mile Problem (Navigation))

The navigation challenge that occurs when GPS or other positioning systems bring a person with a visual impairment to the general vicinity of their destination (typically within 5-10 meters) but cannot guide them to the precise location, such as a specific entrance, storefront,…

Laterality(also: Left-Right Discrimination, Lateral Awareness)

Laterality is the ability to distinguish between left and right sides of the body and to apply this understanding to the surrounding environment for spatial orientation and navigation. Laterality is a fundamental spatial cognition skill that underpins many daily activities, from…

Legally Blind(also: Legal Blindness)

A legal classification of visual impairment used to determine eligibility for government benefits, rehabilitation services, and disability accommodations. In the United States, legal blindness is defined as visual acuity of 20/200 or worse in the better eye with best correction,…

Listenability(also: Auditory Readability, Speech-Output Quality)

A web-accessibility usability metric that measures how appropriate a page's rendered text is when read aloud by a screen reader or voice browser — complementary to, and distinct from, raw WCAG conformance. Listenability penalises meaningless or placeholder ALT text (such as…

Loss of Obscurity(also: Loss of anonymity)

A concept introduced by Thomas J. Carroll in his 1961 book "Blindness: What It Is, What It Does, and How to Live with It," in which he identified twenty distinct losses that accompany the onset of blindness. Loss of obscurity refers to the unavoidable conspicuousness of carrying…

Macro-Navigation(also: Macro Navigation)

The process of navigating through the broader environment at the level of routes, streets, landmarks, and destinations — knowing where you are in a city, which direction to travel, and how to reach a distant goal. In contrast to micro-navigation (detecting immediate obstacles…

Mathematical Accessibility(also: Math Accessibility, STEM Accessibility)

The practice of making mathematical notation, formulas, equations, and quantitative content accessible to people with disabilities, particularly blind and low-vision users. Mathematical notation poses unique accessibility challenges because it is inherently visual and…