Before you can control your voice, you need to understand what it’s doing.
Here’s how the system actually works.
1) How Sound Begins
Air pressure builds below the vocal folds (subglottal pressure).
That pressure gently pushes the vocal folds apart.
Their elasticity — combined with the pressure drop as air escapes — brings them back together.
This open–close cycle repeats hundreds of times per second. That rapid vibration creates sound waves.
The vocal folds touch briefly during each cycle in normal voicing but they are not clapping forcefully together. Healthy singing involves efficient vibration, not impact.
2) How Pitch Changes
Pitch depends on three vocal fold variables:
- Length
- Tension
- Vibrating mass
Two key muscles adjust these:
Thyroarytenoid (TA) → shortens and thickens the vocal folds
Cricothyroid (CT) → lengthens and stretches the vocal folds
Longer + tighter = faster vibration = higher pitch
Shorter + thicker = slower vibration = lower pitch
The activity of these muscles determines the vibratory patterns
3) Changing tone
Two of the most important variables when it comes to tone are:
- Thickness of vibration (M1 vs M2)
- Edge closure (clear vs breathy)
Keep these separate. Most confusion comes from blending them together.
4) Thickness of Vibration — M1 vs M2
M1 (Chest / Modal)
- TA engaged
- Thicker fold body involved
- Deeper vertical vibration
- Larger amplitude
- Longer closed phase
- Stronger contact
M1 can be heavy and dense.
It can also be light and speech-like.
Volume does not define mechanism.
You can sing M1 quietly or loudly.
As pitch rises, CT activity increases. The folds lengthen and the effective vibrating mass reduces — even if you remain in M1.
M2 (Head / Falsetto)
- Inactive/reduced TA contribution
- Thin, cover-dominant vibration
- Shallower mucosal wave
- Smaller amplitude
- Shorter or minimal closed phase
- Reduced contact force
Less tissue vibrates each cycle, which often creates a lighter tonal quality.
Important: M2 can be very loud.
Strength in M2 comes from:
- Efficient closure
- Resonance tuning
- Acoustic back-pressure
- Vowel shaping
- Balanced airflow
Both M1 and M2 can overlap across pitch ranges.
The voice typically shifts toward a thinner configuration when the thicker setup becomes inefficient.
5) Clear vs Breathy — Closure Pattern
Independent of M1 or M2.
If the vocal fold edges meet fully → clear tone
If they do not meet → breathy tone
You can have:
- Clear M1
- Breathy M1
- Clear M2
- Breathy M2
Breathiness simply means incomplete edge contact.
It is not a register issue but the change in breathiness can confuse the singer in regard to which vibratory mode they’re in; M1 or M2.
6) How Resonance Assists the vocal Folds
The vocal tract shapes sound after it leaves the vocal folds.
Proper shaping creates acoustic back-pressure, which:
- Assists fold closure
- Stabilises thin folds (especially M2)
- Increases loudness without pushing
- Reduces breathiness
If a note feels difficult, vowel adjustment often solves it faster than added effort.
7) Airflow — The Balancing Variable
Too Much Airflow
- Blows the folds apart
- Causes breathiness
- Destabilizes pitch
- Encourages squeezing
Too Little Airflow
- Irregular vibration
- Tight sensation
- Upper-range cracks
- Strain
Balanced Airflow
- Stable pitch
- Clean closure
- Efficient tone
M1 needs sufficient pressure to open thicker folds — not excessive airflow.
M2 requires less pressure, but still demands efficient closure.
The goal is not “more air.”
The goal is balanced pressure and flow.
(SOVT exercises can help).
The System in Six Lines
M1 → thicker folds (greater TA contribution)
M2 → thinner folds (reduced TA contribution)
Clear tone → full edge closure
Breathy tone → incomplete closure
Airflow must match thickness
Resonance and SOVTs improve closure efficiency
This is a coordination system.
If you want structured guidance applying this system to your own voice, book a 1:1 session. We assess your mechanism, closure, airflow balance, and resonance strategy — and build a plan.
