Glossary

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Acoustic Event Detection(also: Sound Event Detection, Audio Event Detection, Sound Event Classification)

The automated process of identifying and classifying specific sounds within an audio stream, such as recognizing a phone ringing, door knocking, fire alarm, or speech from continuous environmental audio. Acoustic event detection systems use machine learning trained on labeled…

Acoustic Phonetics

The branch of phonetics concerned with the physical properties of speech sounds, including their production, transmission, and perception as acoustic signals. Acoustic phonetics uses techniques such as spectral analysis, formant tracking, and landmark detection to characterize…

Fuzzy Logic(also: Fuzzy Inference)

Fuzzy logic is a form of many-valued logic that deals with approximate reasoning, where truth values range continuously between 0 and 1 rather than being strictly true or false. In assistive technology and signal processing, fuzzy logic systems are used to handle imprecise or…

Imagined Voluntary Movement-Related Potentials(also: IVMRPs, Motor Imagery Potentials)

Electrical brain signals generated when a person imagines performing a voluntary movement without actually executing it. These potentials, detectable via EEG electrodes placed over motor cortex areas, are similar in pattern to the signals produced during actual movement. IVMRPs…

Landmark Detection(also: Acoustic Landmark Detection, Stevens Landmark Theory)

Landmark detection is a speech analysis method based on Kenneth Stevens' acoustic model of speech production, which identifies perceptually significant points in the acoustic signal where listeners extract information about underlying distinctive features. Three primary landmark…

Landmark Theory(also: Stevens Landmark Theory)

A theoretical framework in speech science developed by Kenneth N. Stevens proposing that listeners extract phonetic information from acoustically abrupt events called landmarks in the speech signal. Landmarks mark points of rapid spectral change — such as the release of a stop…

Learning Vector Quantization(also: LVQ)

A supervised machine learning algorithm used for pattern classification, commonly applied in brain-computer interface systems to classify EEG signals. LVQ works by creating a set of reference vectors (codebook) that represent decision boundaries between different classes of…

Mean Power Frequency(also: MPF, Mean Frequency)

Mean power frequency is a single-number summary of a signal's frequency content, computed as the power-spectrum-weighted mean of frequency. In surface-EMG-based accessibility input devices, MPF of each electrode channel is used to discriminate between contractions of nearby…

Mispronunciation Detection(also: Pronunciation Error Detection, Mispronunciation Diagnosis)

Mispronunciation detection is the automated process of identifying errors in a speaker's pronunciation by comparing their speech production against a target or expected utterance. In assistive technology and speech training systems, mispronunciation detection goes beyond simple…

Open Sound Control(also: OSC)

An open, network-based protocol for communication between computers, sound synthesizers, and other multimedia devices, developed by Matthew Wright and Adrian Freed (1997). OSC sends human-readable address patterns and floating-point values over UDP/TCP, offering higher…

Phase-Based Motion Processing(also: Phase-Based Video Motion Processing, Phase-Based Motion Magnification)

A family of computer vision techniques that decompose video frames into complex steerable pyramids and analyse changes in the temporal phase of each scale and orientation to recover motion, including sub-pixel movements invisible to the naked eye. Because it operates in the…

Power Spectral Density(also: PSD, Power Spectrum)

Power spectral density describes how the power of a time-varying signal is distributed across frequency components. It is a foundational tool in signal processing and shows up repeatedly in accessibility technology: in EMG-based input devices, PSD analysis of electrode signals…

RSSI Fingerprinting(also: Received Signal Strength Fingerprinting, Radio Fingerprinting, Signal Fingerprinting)

An indoor localization technique in which a device estimates its position by comparing the current pattern of received signal strengths (RSSI) from surrounding radio sources — most commonly Bluetooth Low Energy beacons or Wi-Fi access points — against a pre-collected map of…

Signal Drift(also: Baseline Drift, DC Drift)

Signal drift is the gradual, unintended change in the baseline level of a measured signal over time, caused by factors unrelated to the intended measurement. In bio-electrical sensing for assistive technology, drift is a major challenge — for example, in electrooculography…

Spatio-Temporal Modulation(also: STM)

A rendering technique used in mid-air ultrasound haptics in which a single focal point is moved rapidly along a closed trajectory (commonly circular) while its intensity is modulated over time. When the trajectory is swept fast enough (typically tens to hundreds of Hz), the skin…

Spectrogram(also: Sonogram, Spectral Display)

A spectrogram is a visual representation of the frequency spectrum of a signal as it varies over time, typically showing time on the horizontal axis, frequency on the vertical axis, and intensity represented by color or brightness. In speech science and accessibility research,…

Voice Conversion(also: VC, speech conversion)

A speech processing technique that transforms one person's voice to sound like another while preserving the linguistic content. In accessibility applications, voice conversion can improve the intelligibility of speech from people with articulation disorders by replacing unclear…

17 results.