Weeks 5-6 · technique · sustained vowel with free articulators
Hold /a/ for four seconds — jaw soft, tongue forward and flat.
The rule
pass: 4s · SD ≤ 30¢ · drift ≤ 8 dB · jaw + tongue ≤ 2
Two things must be true. Up top, the pitch trace stays inside the ±30¢ band for the full 4 seconds — clenched jaw or retracted tongue shows up as pitch jitter that drifts out of band. Below, both self-ratings sit in the emerald 0-2 range; anything 3+ is clenched and fails. Audio AND ratings.
Hear it first
A free /a/ rings — the vowel sounds open and the pitch sits dead still. A clenched /a/ sounds tighter and the pitch shimmers, usually slightly sharp from the compressed vocal tract.
What’s happening. Per Estill body-use, jaw and tongue tension distort vowels (the tract shape that filters voicing into a recognisable vowel) and cap range (a gripped jaw transmits tension into the larynx). Released articulators let the voice resonate; clenched ones add ~20¢ of audible pitch jitter from micro-tremors in the suspensory muscles.
Why both axes. A steady tone alone can be faked with white-knuckle tension — the audio passes but the body is wrong. The self-rating catches that. Conversely, you can have a relaxed jaw and still wobble pitch — the audio rule catches that. Requiring both keeps you from cheating either way. Camera mirror is on by default so you can see your jaw.
Why this is the foundation. Vowel switching, vowel modification on ascent, bright/narrow resonance, and all the late-curriculum repertoire work assume free articulators. Without that, your vowels collapse on high notes and your range stays narrow. Settle this here so every later vowel-quality drill starts from a free baseline.
Session ahead
5 trials · 4s sustain on /a/ · audio (SD ≤ 30¢ + drift ≤ 8 dB) AND self-rated jaw + tongue ≤ 2 · hit 4 to advance.