Glossary
Terms used in accessibility research and practice. Each entry has a definition, common aliases, and category tags.
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- Acoustic Accessibility(also: Sound Accessibility)
- An emerging framing of accessibility that considers a user's full acoustic environment - which sounds reach them, how loud, and in what mix - as a design surface to be adapted to individual sensory needs rather than treated as fixed background. While hearing accessibility has…
- Active Noise Cancellation(also: ANC, Active Noise Control)
- A technique that reduces unwanted ambient sound by using microphones to capture incoming noise and electronically generating an inverted (anti-phase) audio signal that destructively interferes with it, lowering the perceived noise reaching the listener's ear. ANC is the core…
- Audio Interference(also: Audio Conflict, Speech Conflict)
- Audio interference in a digital accessibility context is the overlap of two or more sound streams in a user's environment such that one masks another — most commonly, auto-playing media audio on a webpage drowning out a screen reader's synthesized speech. Because most consumer…
- Audio Tone(also: Auditory Cue, Earcon)
- Non-speech audio signals used to convey information such as the presence, location, or status of objects or interface elements. In accessibility contexts, audio tones can supplement or replace verbal descriptions, similar to how screen readers like JAWS use different sound…
- Auditory Description(also: Audio Description, Spoken Description, Verbal Description)
- The practice of providing spoken narration that describes visual information, making content accessible to people who are blind, have low vision, or benefit from auditory reinforcement of visual content. Auditory description has evolved from pre-recorded narration for film and…
- Auditory Masking(also: Sound Masking, Acoustic Masking)
- A perceptual phenomenon where the presence of one sound makes it difficult or impossible to hear another sound. Masking occurs when sounds share similar frequencies or when a louder sound overwhelms a quieter one. In accessible design, understanding auditory masking is essential…
- Background Noise(also: Ambient noise, Environmental noise)
- The sum of unwanted or competing sound in an environment — traffic, construction, conversation, HVAC systems, weather — that is present alongside a signal of interest. Background noise is characterized by sound level (dB), spectral content, duration, and steadiness versus…
- Bone Conduction(also: Bone Conduction Headphones, Bone Conduction Audio)
- A method of transmitting sound vibrations through the bones of the skull directly to the inner ear, bypassing the outer and middle ear. Bone conduction headphones rest on the cheekbones or temples rather than covering or inserting into the ears, leaving the ear canals open to…
- Frequency Selectivity(also: Auditory Frequency Resolution, Critical Band Selectivity)
- Frequency selectivity is the auditory system's ability to separate closely-spaced frequencies into distinct perceptual streams — the reason a typical listener can follow one voice in a crowd, hear the bass line under a melody, or distinguish similar speech sounds like 's' and…
- Interactive Description(also: Dynamic Description)
- A design approach for providing accessible descriptions of interactive digital content that updates in real time as users navigate and manipulate elements. Unlike static alternative text, interactive descriptions consist of two complementary structures: state descriptions that…
- Listening Rate(also: Comprehension Speed, Listening Speed)
- The maximum speed at which an individual can accurately comprehend spoken or synthesized speech, typically measured as a normalized value or in words per minute. Research shows that experienced screen reader users can achieve listening rates far exceeding typical human speech…
- Loudness Recruitment(also: Recruitment, Hyperacusis-like Recruitment)
- Loudness recruitment is a common consequence of sensorineural hearing loss in which the range between 'just audible' and 'uncomfortably loud' sounds is compressed — quiet sounds are harder to hear, but sounds above threshold grow louder more rapidly than in a typical listener.…
- Semantic Hearing(also: Programmable Hearing, Intent-Aware Hearing)
- A research paradigm and class of systems that treat the user's auditory environment as something programmable: rather than uniformly amplifying or suppressing all sound, the wearable headphone or earbud uses on-device machine learning to selectively extract or attenuate specific…
- Sound Pressure Level(also: SPL, Decibel Level)
- A logarithmic measure of sound intensity expressed in decibels (dB), representing the pressure of a sound wave relative to a reference level. In accessibility, SPL is critical for designing auditory feedback systems—sounds must be loud enough to be detected above ambient noise…
- Speech Intelligibility(also: Speech Recognition Score, Word Recognition)
- A measure of how well speech can be understood by a listener, typically expressed as the percentage of words or sentences correctly identified under specific listening conditions. Speech intelligibility is affected by factors including audio bandwidth, background noise, signal…
- Speech Rate(also: Speaking Rate, Articulation Rate)
- The speed at which speech is produced, typically measured in words per minute (WPM) or syllables per second. Normal conversational speech ranges from 120-180 WPM, while screen reader users often configure synthetic speech at rates of 300-400 WPM or higher. Speech rate settings…
- Target Sound Extraction(also: Target Sound Separation, TSE)
- A machine-learning task in which a model isolates a specific target sound (or class of sounds) from a complex acoustic mixture, conditioned on some specification of the target - a text label, a reference recording, or an embedding. Distinct from blind source separation (which…
- Time-compressed Speech(also: Accelerated Speech, Speed-altered Speech)
- Speech that has been digitally processed to play at a faster rate than it was originally recorded or synthesized, while preserving pitch. Unlike simply increasing playback speed (which raises pitch), time compression algorithms remove small portions of the audio signal to reduce…
- Voicemail(also: Voice Mail, Voice Messaging)
- Voicemail is a telecommunications service that records an audio message from a caller when the called party is unavailable, for later retrieval by the recipient. Accessibility considerations include: reliance on hearing to listen to messages (a barrier for Deaf and…
- White Noise(also: Broadband Noise)
- A sound signal containing equal intensity across all audible frequencies, perceived as a constant hissing or static sound. In accessibility applications, white noise is valued for its localization properties—the broadband frequency content makes it easier for listeners to…
- Words Per Minute(also: WPM)
- A standard measure of speech or reading speed, representing the number of words produced or comprehended in one minute. Typical human speech occurs at 120-180 WPM, average reading speed is 200-250 WPM, while experienced screen reader users can comprehend synthesized speech at…
21 results.