Glossary
Searchable terminology from accessibility, web standards, and related fields.
62 results found in Speech Technology.
- AI-Generated Speech (Synthetic Speech, AI Speech)
- Speech audio produced by artificial intelligence systems — typically neural text-to-speech or voice cloning models — rather than recorded from a human speaker. Deaf and hard-of-hearing content creator…
- Acoustic Analysis (Acoustic Signal Analysis)
- The computational examination of sound signals to extract measurable properties such as duration, fundamental frequency (pitch), intensity, spectral characteristics, and formant structure. In accessib…
- Acoustic Model (AM)
- An acoustic model is the component of an automatic speech recognition (ASR) system that maps short segments of audio (typically 10–25 ms frames of spectral features) to the linguistic units that produ…
- Canonical Syllable (Canonical Babbling, Well-Formed Syllable)
- A canonical syllable is a well-formed syllable in infant babbling that consists of a consonant-like closure (closant) produced by an oral cavity constriction followed by a vowel-like opening (vocant).…
- Computer Feedback System (CFS, Computerized Feedback System)
- A technology system that detects a user's behavior — such as vocalizations, movements, or physiological signals — and provides immediate audio, visual, or haptic responses mapped to that behavior. In …
- Computer-Assisted Language Learning (CALL, Computer-Aided Language Learning)
- Computer-Assisted Language Learning (CALL) refers to the use of computers and digital technology to support language education and pronunciation training. CALL systems often incorporate automatic spee…
- Computer-Based Speech Training (CBST, Computer-Aided Speech Training, CAST, Speech Training Software)
- Computer-based speech training (CBST) refers to software systems designed to help individuals improve their speech production through automated exercises, feedback, and practice. These systems typical…
- Concatenated Speech Synthesis (Concatenative Synthesis, Unit Selection Synthesis)
- A method of producing synthetic speech by connecting pre-recorded segments of human speech, typically diphones (transitions between phonemes) or demi-syllables, to form complete words and sentences. C…
- Concatenative Synthesis (Unit Selection Synthesis)
- A text-to-speech method that generates synthetic speech by concatenating (joining together) pre-recorded segments of human speech. These segments, called units, may be phonemes, diphones, syllables, o…
- DECTalk
- A text-to-speech synthesis system originally developed by Digital Equipment Corporation in the 1980s, using rule-based formant synthesis to generate speech from text input. DECTalk offered several pre…
- Data-based Synthesis (Corpus-based Synthesis, Unit Selection Synthesis)
- A speech synthesis technique that generates speech by selecting and concatenating segments from a large database of prerecorded human speech, rather than using rules to generate acoustic waveforms fro…
- Deaf-Accented Speech (Deaf Accent, Deaf-Accented English)
- Speech produced by Deaf or Hard of Hearing people whose articulation, prosody, and voicing patterns differ from typical hearing speakers because the speaker has limited or no auditory feedback for the…
- Diphone (Diphone Synthesis)
- A unit of speech used in text-to-speech synthesis, consisting of the transition from the middle of one phoneme to the middle of the next. Diphone-based synthesis works by recording a set of all possib…
- Dragon NaturallySpeaking (Dragon Dictation, Dragon Speech Recognition, Nuance Dragon)
- Dragon NaturallySpeaking is a commercial speech recognition software product, originally developed by Dragon Systems and later acquired by Nuance Communications (now part of Microsoft). It converts sp…
- DragonDictate (Dragon Dictate)
- An early discrete speech recognition system developed by Dragon Systems that allowed users to control computers and dictate text by speaking one word at a time with brief pauses between words. Release…
- ElevenLabs
- A commercial AI voice platform that generates realistic synthetic speech and voice clones from text. ElevenLabs is used in accessibility contexts for producing narrated video voiceovers, audiobook-sty…
- Endpoint Detection (Voice Activity Detection, VAD)
- The process by which a speech-recognition system decides when a user has finished speaking, so the system can stop listening and send the captured audio for recognition. Off-the-shelf voice assistants…
- Forced Alignment (Phonetic Alignment, Phone-Level Alignment)
- Forced alignment is an automatic speech processing technique that aligns a speech recording with its known transcription at the phoneme or word level. Unlike free speech recognition which determines t…
- Formant Synthesis (Rule-based Synthesis, Parametric Synthesis)
- A text-to-speech method that generates synthetic speech by modeling the acoustic properties of human vocal production, particularly formants (resonant frequencies of the vocal tract). Rather than usin…
- Gaussian Mixture Model (GMM)
- A Gaussian Mixture Model (GMM) is a probabilistic model that represents data as a weighted combination of multiple Gaussian (normal) distributions. Each component Gaussian has its own mean and covaria…