Envelope extraction isolates the slow-varying amplitude contour of a signal by computing its short-time spectral magnitude, finding local maxima across successive frames, and smoothing the peak trajectory with a low-pass filter or moving average. It operates on the principle that envelope changes are orders of magnitude slower than carrier oscillations. Persistence mechanism: peak-tracking algorithms (half-wave rectification + low-pass filtering, Hilbert transform analytic signal, Viterbi trellis tracking) implemented in DSP libraries and speech processing toolkits. [formal: extrahatio | substrate: behavior | horizon: hours | explicit: yes | epoch: 1.02]
Accepted ontology entry
envelope-extraction
Envelope extraction isolates the slow-varying amplitude contour of a signal by computing its short-time spectral magnitude, finding local maxima across successive frames, and smoothing the peak trajectory with a low-pass filter or moving a…
Definition
Why it is in scope
A human-made signal processing technique that isolates the slow-varying amplitude envelope of a signal by tracking local maxima of its short-time spectral energy, built to persist through peak-tracking algorithms used in speech synthesis and audio analysis.
Names and aliases
- envelope-extractionen · CANONICAL
Relations from this entry
- cmspg0fzk056ijlss3ydafq7bDERIVED_FROM →
Envelope extraction via spectral peak-tracking derives from short-time spectral analysis (1940s STFT). The method of computing short-time spectra then tracking local maxima depends on the spectral decomposition techniques that spectral analysis established. The analysis→synthesis pipeline structure originates in spectral analysis.
- cmsr5132h0091kp532460fn95INSTANCE_OF →
envelope-extraction IS a specific kind of amplitude analysis: it extracts the amplitude envelope of a signal as one of several amplitude characterization methods. Specific→general per Law 9.
- cmspqj6jh0677jlssnhgl6v8dDEPENDS_ON →
Envelope extraction needs magnitude-spectrum to operate: it computes the slow-varying amplitude envelope from spectral magnitude data. Remove magnitude-spectrum and envelope extraction has no data domain. Removal test passes.
Relations to this entry
- cmsrq3mlc0008sk5348kt4kl9← DEPENDS_ON
Removal test: onset-detection operates by computing a time-varying energy or spectral feature (envelope) and locating peaks above threshold. Remove envelope-extraction and the technique has no mechanism to produce the feature function it analyzes — it stops operating entirely.
Record identity
- Created
- Aug 13, 2026, 4:29 AM UTC
- Content hash
- b7289fce2e50e74bbdaf157f83ef12bf79ec15f8f1f0d838508865c88441a334