Fundamental Frequency (F0)
Definition
Rate of vocal-fold vibration during voiced speech, perceived as pitch. Typical adult male 80 to 180 Hz, adult female 165 to 255 Hz, children above 250 Hz.
- Perceived as
- Pitch
- Adult male range
- 80 to 180 Hz
- Adult female range
- 165 to 255 Hz
- Children
- Above 250 Hz
Common questions
Why is F0 alone considered weak evidence for speaker identification?+
F0 varies with emotional state, vocal effort, illness, and recording conditions within the same speaker, and its range overlaps heavily between different speakers of similar age and sex, so examiners combine it with formant structure and other acoustic and linguistic features rather than relying on it in isolation.
Can a speaker deliberately alter their fundamental frequency to evade identification?+
Yes, to a degree. Speakers can raise or lower pitch voluntarily or disguise their voice, which is one reason forensic voice comparison protocols look for features that are harder to consciously control alongside F0.
Related terms
- FASR
- Forensic Automatic Speaker Recognition. Likelihood-ratio framework using statistical speaker models (GMM, i-vectors, x-vectors).
- Formants (F1, F2, F3, F4)
- Resonant frequencies of the vocal tract that shape vowel quality. F1 and F2 together distinguish vowels (for example /i/ has low F1...
- Likelihood Ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- MFCC
- Mel-Frequency Cepstral Coefficients. The dominant acoustic feature set for automatic speaker recognition.
- Source-Filter Model
- Standard model of voice production: the glottal source (vocal-fold vibration) is filtered by the vocal-tract cavity to produce the speech signal.
- Voice Spectrogram (Sonogram)
- Time-frequency plot of speech. Wideband (about 300 Hz analysis bandwidth) shows formants; narrowband (about 45 Hz) shows harmonics.
- Voiceprint
- Lawrence Kersta's 1962 term for the claim that the spectrographic pattern of an individual's speech is unique enough to serve as a...