WHAT THIS IS

A vocal tract made of an Ariadne World, after Neil Thapen's Pink Trombone (2017), written independently. Nothing here plays a recording or a stored glottal pulse: lung pressure pushes air through two folds, the folds start to flap on their own, and the flapping air rings in a tube shaped by your tongue, lips and velum. Every joule is on the books: what the breathing muscles and the orbs put in, what moving the walls cost, what was lost to the walls, the jet and the folds, and what left through the lips and nostrils. The residual is printed above.

PHYSICAL (ARIADNE CONSTITUTION)

• An oral tube of 44 sections and a nasal tube of 31 (at 48 kHz), travelling pressure waves, lossless junctions; the velum is a lossless three-way junction.
• The area function (GARGANTA's neutral tract, plus a movable tongue, lips and velum) is a configuration the World is moved through with the waves held fixed; the energy that changes is booked as control work, as frets and the trombone slide are in Ariadne.
• The glottis self-oscillates: a fold mass on a tension spring with collision, pushed by the air in the slit, fed by a finite lung reservoir the breathing muscles refill. Pitch is the fold tension; the World decides the actual F0 (it rises with breath).
• An orb is a touch: it knocks the air where it lands (its energy is source work) and dents the wall, which wobbles back (control work). With no breath you hear the tube's own resonances.
• Lips and nostrils are radiating air plugs; the sound you hear is the pressure they emit, read without loading them.

APPROXIMATED, AND WHY

• Not an instance of mus_ariadne::World: its bodies are 24-mode modal fields on a one-dimensional configuration path, and a branching waveguide with a three-dimensional configuration does not fit. The tract follows the same constitution in its own crate, ovillo-tract, with Ariadne's ledger type.
• Wall loss is frequency independent; radiation matches GARGANTA's low-frequency radiation load and departs from it above about ka = 1.
• One fold mass with a lumped mucosal delay, not a two-mass or continuum fold. The air's work on the folds is booked to the lungs without resolving its path through the slit.
• Closures stop at GARGANTA's 0.025 cm² floor: no exact closure, no cavity split. Breathiness is turbulence noise paid out of the jet's own loss, not a resolved flow.
• The nasal passage is a design hypothesis; vowel presets are fit so the tube's resonances sit on GARGANTA's rung-1 vowel bodies (design profiles, not measurements). An open glottis lifts the voiced /i/ and /u/ F1 above the target.
• The pictures: geometry follows the World every frame (areas, fold gap, wall pressure). The idle sway of the camera, the sheen and the orb splashes are decoration. The folds are drawn from the last measured cycle, slowed like a stroboscope.

Source: ovillo/crates/ovillo-tract (World, tests, receipts) and ovillo/crates/ovillo-tract-wasm (C ABI). three.js r170 is vendored under vendor/three/ with its MIT license.