Glossary
Searchable terminology from accessibility, web standards, and related fields.
17 results found in telecommunications.
- Adaptive Multi-Rate Codec (AMR, AMR Codec, AMR-NB, AMR-WB)
- A family of audio codecs used in mobile telephony to encode voice for transmission. AMR-NB (narrowband) operates at 300-3,400 Hz with bit rates from 4.75-12.2 kbps, while AMR-WB (wideband, also called…
- Hearing Aid Compatibility (HAC, HAC Rating)
- Federal Communications Commission (FCC) requirements and ratings for telephones to work effectively with hearing aids and cochlear implants. HAC standards address acoustic coupling (how well the phone…
- Interactive Voice Response (IVR, Voice Response System)
- A telephony technology that allows users to interact with automated systems using voice commands or keypad input. IVR systems are particularly valuable for accessibility in low-income settings because…
- Mean Opinion Score (MOS, MOS Score)
- A standardized measure of perceived audio or video quality, rated on a scale from 1 (bad) to 5 (excellent). In telecommunications research, MOS is commonly used to assess speech quality as experienced…
- Narrowband Audio (NB Audio, Standard Definition Voice)
- Audio transmission limited to the frequency range of approximately 300-3,400 Hz, which has historically been the standard for telephone networks (PSTN). While sufficient for basic speech intelligibili…
- Packet Loss (Network Packet Loss, Data Loss)
- The failure of data packets to reach their destination during network transmission, common in VoIP and mobile telephony. Packet loss causes audio dropouts, distortion, and reduced intelligibility. Res…
- Remote interpreting (Video remote interpreting, VRI, Remote sign language interpreting)
- The provision of sign language interpretation or other communication access services through video technology, where the interpreter is located in a different physical space from the deaf or hard of h…
- Speech Intelligibility (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 intelligibili…
- Telecoil (T-Coil, Telephone Coil, Induction Coil)
- A small copper coil inside a hearing aid or cochlear implant processor that picks up magnetic signals and converts them to sound. Telecoils allow hearing device users to receive audio directly from te…
- Telecommunication equity (Communication equity, Functional equivalence)
- The principle that people with disabilities should have access to telecommunications services that are functionally equivalent to those available to people without disabilities. For deaf users, this m…
- Telecommunications Device for the Deaf (TDD, TTY, Text Telephone, Teletypewriter)
- A specialized device that enables text-based telephone communication for people who are deaf or hard of hearing. TDDs transmit typed text over telephone lines using acoustic coupling or direct connect…
- Video Conferencing (Videoconferencing, Video Teleconferencing, Video Call)
- Real-time visual and audio communication between two or more people at different locations using video cameras, displays, and network connections. Video conferencing has significant accessibility impl…
- Video Relay Service (VRS)
- A free, subscriber-based telecommunications service regulated by the Federal Communications Commission (FCC) in the United States that enables deaf individuals who use sign language to make phone call…
- Video intelligibility (Signal intelligibility, Visual signal clarity)
- The degree to which a video signal can be perceived and understood by the viewer, determined by technical parameters including frame rate, bit rate, spatial resolution, and codec quality. Video intell…
- Video relay service (VRS)
- A telecommunications service that enables deaf and hard-of-hearing sign language users to communicate with hearing people via telephone through a video link with a sign language interpreter. The deaf …
- Voice over Internet Protocol (VoIP, IP Telephony, Internet Calling)
- Technology that enables voice communication over internet networks rather than traditional telephone lines. VoIP converts voice signals into digital packets transmitted over IP networks, enabling feat…
- Voice over LTE (VoLTE, LTE Voice, HD Voice)
- A standard for transmitting voice calls over 4G LTE mobile networks using IP-based protocols rather than legacy circuit-switched networks. VoLTE typically uses the AMR-WB codec, enabling wideband HD v…