Sing a steady Om on your most comfortable pitch.
Hold it ~1.5 seconds. That becomes your Sa.
Idle
Tip: low/mid voice register works best. Can always re-calibrate from the 🎤 button.
Svara Training
Calibrate OM, then learn to hold the three svaras — Anudātta (low), Udātta (home), Svarita (high). Watch a lotus track your pitch across body resonance zones.