Source–Filter Model (Fant, 1960): Voice = Glottal Source × Vocal Tract Filter × Radiation.
The glottal source is a Rosenberg-type asymmetric pulse — slow open, fast close — producing harmonics decaying at ~12 dB/octave.
G(t) = 0.5(1 − cos(πt/Tp)) for open, cos(π(t−Tp)/2Tn) for close
Infant Vocal Tract: ~8 cm (vs adult ~17 cm), resonances ~2× higher: F1 ≈ 1100 Hz, F2 ≈ 3300 Hz, F3 ≈ 5000 Hz.
F0 Range: Normal infant cry F0 ≈ 200–800 Hz (typical ~449 Hz). Cry melody follows a rising–falling contour.
Jitter & Shimmer: Cycle-to-cycle perturbations in period (~1-3%) and amplitude (~3-8%).
Real-time: Native Web Audio oscillator bank + BiquadFilter formants. All parameters update live — twist the knobs while it cries!