Formant
Formants are characteristic peaks in the frequency spectrum, independent of the fundamental frequency. Each vowel has different peaks in the energetic spectrum of the sound. They are identifiable through the Spectral Envelope of an utterance.
Each peak represents a formant, where the first peak is called formant 1 (F1), the second formant 2 (F2), and so on. Phonemes are differentiated well by their first and second formant. The following gives the topology of phonemes in the space of formant 1 and 2:
![[Pasted image 20240625104446.png]]
| German vowel | IPA | Formant F1 | Formant F2 |
|---|---|---|---|
| U | u | 320 Hz | 800 Hz |
| O | o | 500 Hz | 1000 Hz |
| å | ɑ | 700 Hz | 1150 Hz |
| A | a | 1000 Hz | 1400 Hz |
| ö | ø | 500 Hz | 1500 Hz |
| ü | y | 320 Hz | 1650 Hz |
| ä | ɛ | 700 Hz | 1800 Hz |
| E | e | 500 Hz | 2300 Hz |
| I | i | 320 Hz | 3200 Hz |
The different formants of a vowel are produced in different resonance chambers of the vocal tract.
| Formant | Frequency range (male) | Associated resonance chamber |
|---|---|---|
| F0 | 80–200 Hz | Vocal folds, voice |
| F1 | 220–780 Hz | Pharynx |
| F2 | 1200–2000 Hz | Oral cavity |
| F3 | 2200–3000 Hz | Lip region |
| F4 | 3350–5100 Hz | Coronal space (space behind the maxilla and zygomatic bone) |
Formants can be acoustically modeled through the Source-Filter Model#Tube Model of the Vocal Tract.