Glossary
Searchable terminology from accessibility, web standards, and related fields.
16 results found in Signal Processing.
- Acoustic Event Detection (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 aud…
- 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 a…
- Fuzzy Logic (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 technolog…
- Imagined Voluntary Movement-Related Potentials (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,…
- Landmark Detection (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 ex…
- Landmark Theory (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. L…
- Learning Vector Quantization (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 …
- Mean Power Frequency (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 eac…
- Mispronunciation Detection (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 technol…
- Open Sound Control (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 add…
- Phase-Based Motion Processing (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 …
- Power Spectral Density (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 accessibil…
- RSSI Fingerprinting (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 …
- Signal Drift (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 te…
- Spatio-Temporal Modulation (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 t…
- Spectrogram (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 repr…