Sing sing

Tract Star: Discover the physics of your voice Your voice is an instrument unlike anyone else’s. Your singing coach should understand how it works - but even the best human singing coaches rely on what they hear, and what they can see on the outside. They can't look under the hood. Tract Star combines iPhone LiDAR, active acoustic probing and physical simulation to build a personalized model of your vocal instrument - with Astra as its scientific brain. Most singing apps measure pitch and tell you to try again. Tract Star investigates why your voice sounds the way it does, then uses that understanding to guide your next experiment. We turn your phone into a vocal research lab. LiDAR captures visible geometry that helps distinguish anatomical hypotheses. Our sound-sweep method sends a known acoustic signal and analyzes its response, adding information that ordinary singing recordings alone cannot provide. A native vocal-tract simulator then tests competing explanations for how anatomy, articulation and sound production interact. Astra closes the loop. It examines the evidence, chooses an informative next exercise, explains what to try and incorporates the results. Predictions are frozen before the next recording, so each attempt becomes a real test of the model—not a story invented afterward. The technical challenge is connecting fundamentally different signals: depth measurements, acoustic responses, recorded voice and simulated physiology. We bring them into one experimental system that can compare alternatives, update its understanding and make the mechanics of singing tangible. We’re not using Astra to put a chatbot on a pitch detector. We’re using it to orchestrate a personalized physics lab for the human voice.