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Non-stationary noise

Definition

Interference whose spectral content changes over time: a vehicle passing, a crowd noise that rises and falls, or a door slamming. Adaptive filtering is required because a fixed noise estimate based on a single silent interval will not model the interference throughout the recording.

Related terms

PESQ / STOI
Perceptual Evaluation of Speech Quality and Short-Time Objective Intelligibility: instrumental measures that predict listener intelligibility without needing human subjects. STOI scores between...
Spectral subtraction
An enhancement method that estimates the noise spectrum during a speech-free interval and subtracts it from every subsequent frame. Simple and effective...
Stationary noise
Noise whose spectral characteristics remain approximately constant over the duration of a recording. Tape hiss, HVAC fan noise, and mains hum are...
SWGDE
Scientific Working Group for Digital Evidence: a US-based body that publishes best-practice guidelines for forensic audio, video, and image examination. Its audio...
Wiener filter
A minimum mean-squared-error filter that computes a frequency-dependent gain function from the signal-to-noise ratio in each frequency band. Less aggressive than spectral...

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