Fundamental frequency (F0) is the lowest frequency of a periodic waveform, representing the rate at which the sound source repeats its cycle. In speech, it corresponds to vocal fold vibration rate; in music, to the perceived pitch of tonal sounds. F0 is estimated through time-domain methods (autocorrelation, average amplitude difference) or frequency-domain methods (cepstral analysis, spectral peak picking). The concept picks out the fundamental from its harmonics (integer multiples), and persists through estimation algorithms (YIN, SWIPE, pYIN), prosodic annotation frameworks (ToBI), and pitch-tracking conventions in signal processing toolkits. [formal: fundamental frequency | substrate: mind | horizon: a moment | explicit: yes | epoch: 0.01]
Accepted ontology entry
fundamental-frequency
Fundamental frequency (F0) is the lowest frequency of a periodic waveform, representing the rate at which the sound source repeats its cycle. In speech, it corresponds to vocal fold vibration rate; in music, to the perceived pitch of tonal…
Definition
Why it is in scope
A human-constructed acoustic concept denoting the lowest frequency of a periodic sound waveform. Humans built this map to quantify the rate of periodicity in voiced sounds — physically corresponding to vocal fold vibration in speech or string/bore resonance in instruments. The concept persists through measurement conventions, estimation algorithms, and prosodic annotation frameworks across linguistics, musicology, and signal processing.
Names and aliases
- fundamental-frequencyen · CANONICAL
Relations from this entry
- cmsorsyn802qbjlss3cb2ruiyDEPENDS_ON →
Remove the concept of frequency and fundamental-frequency has no quantity to express — F0 IS a frequency value (the lowest of a periodic waveform). The which-came-first test is orthogonal: fundamental-frequency as a specific concept derives from the more general concept of frequency. The removal test is satisfied: without frequency, F0 cannot operate.
- cmsorsyn802qbjlss3cb2ruiyINSTANCE_OF →
Fundamental frequency IS a specific kind of frequency: it is the lowest frequency component of a periodic waveform. A competent speaker would call fundamental frequency a type of frequency. Per Law 9, specific→general.
Relations to this entry
- cmsri7ilz01l9kp538vdq6sma← DEPENDS_ON
Pitch tracking's entire purpose is to estimate the fundamental frequency of a signal over time. The technique operates by detecting F0 — remove F0 as a concept and pitch tracking has nothing to track. DEPENDS_ON at the object level, not meta-level.
- cmsouxg22032pjlssxwjopijt← DEPENDS_ON
Harmonics are defined as integer multiples of the fundamental frequency (n×F0). Remove F0 and harmonics lose their defining reference — there are no harmonics without a fundamental to be multiples of. This is an operational dependency at the object level.
Record identity
- Created
- Aug 13, 2026, 7:35 AM UTC
- Content hash
- 26450e6c0d684300df5cb43332bdd5a7ef5dc049cd818b36f12ff2cc9d52d0dd