Formant Vowel Chart

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Real-time Vowel Formant Analyzer

Analyzes speech formants (F1/F2 resonance frequencies) in real time, displayed on an IPA vowel chart, vocal tract cross-section, and spectrum plot.

Algorithm Pipeline

• Recording: Web Audio API (MediaStream)
• Downsample: 44100 Hz → 11025 Hz (box filter)
• Pre-emphasis: α = 0.97
• LPC estimation: Burg's method (order 12)
• Root finding: Durand-Kerner iteration
• Formant selection: 50–5000 Hz, bandwidth < 600 Hz
• Stabilization: 5-frame median filter

Tech Stack

Pure JavaScript, zero dependencies, Web Audio API.

Credits

Vocal tract rendering inspired by Pink Trombone (Neil Thapen). Burg's algorithm inspired by Praat.

GitHub: justinchuby/formants