Zero-crossing-rate (ZCR) is the count or normalized rate of sign changes in a discrete-time audio signal within a defined analysis window. The parameters are: (1) the window size (typically 20-40ms for speech), (2) the window function applied before counting (usually Hamming or Hanning), (3) whether sign changes at exactly zero are counted (implementation detail that affects edge cases), and (4) normalization method (raw count vs. count per second). The persistence mechanism is algorithmic: ZCR is implemented as a standard computation in audio processing libraries and persists through code in librosa, LibROSA, MATLAB, Praat, and research codebases. It is a foundational feature for audio classification, speech voicing detection, onset detection, and timbre analysis.\n\n[formal: zcr | substrate: behavior | horizon: a moment | explicit: yes | epoch: 0.01]
Accepted ontology entry
zero-crossing-rate
Zero-crossing-rate (ZCR) is the count or normalized rate of sign changes in a discrete-time audio signal within a defined analysis window. The parameters are: (1) the window size (typically 20-40ms for speech), (2) the window function appl…
Definition
Why it is in scope
A signal processing feature that counts how often a discrete-time signal crosses zero amplitude within a fixed window. It is human-made: a numerical metric computed by DSP algorithms for audio analysis, music information retrieval, and speech processing. The technique persists through standardized implementations in audio analysis libraries (librosa, LibROSA, MATLAB) and research protocols. Zero-crossing rate is used to distinguish voiced from unvoiced speech, detect transients, and classify musical instruments.
Names and aliases
- zero-crossing-rateen · CANONICAL
Relations from this entry
- cmsounvj2031ljlss60doj0u5DEPENDS_ON →
Zero-crossing-rate counts the rate at which a waveform crosses zero amplitude. Per Law 8's removal test: remove the waveform and ZCR has nothing to measure — the computation stops operating. Genuine operational dependency.
- cmr9uz3vv00elhcxfruyltnd4INSTANCE_OF →
Zero-crossing-rate IS a specific kind of measurement: it measures the frequency at which a signal crosses zero amplitude, producing a quantitative metric used in audio analysis, speech recognition, and music information retrieval. A competent speaker would call it 'a measurement technique.' Files against nearest kind per Law 9.
- cmrsb393a00miollhxpcc7bkzDEPENDS_ON →
Zero-crossing rate counts how many times the raw signal crosses zero amplitude. Removal test: remove signal and ZCR has no waveform to analyze. Constitutive dependency.
- cmsps9i0v06eejlssqrjcqyviDEPENDS_ON →
Zero-crossing-rate computation needs signal processing to operate — raw signal sampling, noise filtering, and waveform analysis are required. Remove signal processing and ZCR cannot be computed.
- cmrmkhire00hvd1nlzf4w0f8fDEPENDS_ON →
Short-time zero-crossing rate is computed by counting zero crossings within framed segments of a signal. Remove the framing mechanism and short-time ZCR has no operational basis. Constitutive present-tense dependency.
- cmss0y7r700vsh7yuppfym4fzINSTANCE_OF →
Zero-crossing-rate is a specific kind of audio feature — a numerical descriptor computed from audio signals. It IS an audio feature, not something that serves the general category.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Aug 12, 2026, 11:13 AM UTC
- Content hash
- d82d34af01ff4171c7d968bfd2f0728d039b050bef1704b180e0bc2221cdaa78