SonaLab - Real-Time Vocal Analysis Software
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Unstable Closure

闭合力不稳定

SonaLab is a voice analysis and training tool, not a medical device. Symptom detection and scores are for reference only and do not constitute medical advice or diagnosis. Consult a qualified physician for persistent voice discomfort.

Closure comes and goes; the voice flips between breathy and solid.

In One Sentence

Glottal closure fluctuates during phonation — the voice is sometimes airy, sometimes solid. Note: closure force is muscular strength, which audio cannot measure; this uses fluctuations of NAQ (an indirect proxy of closure quality) and can only be phrased as "a tendency of unstable closure".

How to Read It

Watch the Airflow Balance (NAQ) chart. With pitch roughly steady, the hint appears when NAQ swings back and forth within about a second. Light head voice and falsetto naturally run a higher NAQ and may be misjudged.

Why Does This Happen?

CauseDescription
Uncoordinated closureThe folds alternate between loose and tight
Breath and closure out of syncSurging airflow drags the closure along
Inconsistent onsetsEvery onset closes differently

How to Improve

  • Glottal onset: make each onset close the same way
  • Gug arpeggios: hold a steady closure across pitch changes
  • Light head voice and falsetto are naturally airy — not necessarily a problem
  • Related

  • Airflow Balance chart
  • Insufficient Closure