← F2 (Hz) - higher values left
F1 (Hz) ↓
About the Vowel Space
What Is a Vowel Space?
F1 (first formant) correlates with jaw height - low F1 means high tongue. F2 (second formant) correlates with tongue frontness. Plotting F1 vs F2 produces the classic vowel trapezoid used in linguistics.
Reading the Chart
F2 runs right-to-left (high F2 on left = front vowels like /i/). F1 runs top-to-bottom (high F1 at bottom = open vowels like /a/). Faint labels show approximate IPA reference positions.
Only Voiced Frames
Dots are only plotted when pitch is detected - silence, stops, and fricatives are excluded. Older dots fade so the current position is clear.
No ML Model
No machine learning model is used. Formants are extracted with a custom FFT and cepstral analysis. All processing runs locally in your browser and no audio leaves your device.