Estill Model Overview

Power-Source-Filter Model of Voice:

1. Power: Breath involving the lungs, ribs, diaphragm, and abdominal muscles to propel the breath into the vocal tract.
   • System: Respiration
2. Source: The onset of voice using movement of the vocal folds (larynx).
   • System: Phonation
3. Filter: The vocal tract’s modification of sound as it passes through .
   • System: Resonance and amplification

A. Power (Breath)

We breathe in and speak out.

• More power into breath results in a less “clean” and efficient vocal note.
  • Pumping too much into the larynx can contribute to vocal fatigue.

Breathing engages the intercostal muscles between the ribs and your abdomen—

Inhale:

• Diaphragm flattens
• Rib cage expands

Exhale:

• Diaphragm raises
• Rib cage contracts

—so it is important to move you abdomen and chest correctly:

“Imagine breathing inwards to inflate a pool noodle around your waist”  — My friend’s drama teacher

1. Your belly should expand and move forward a little on the in-breath.
   • Tightness in your abdomen causes tightness in the larynx and voice.
2. Abdominal muscles should support the out-breath.
   • Strong/weak pressure impacts the larynx and voice.

B. Source (Larynx)

Following the Path:

1. The outward breath goes from the lungs up the trachea and into the larynx.
2. The true vocal folds of the larynx act like a valve and draw together, fluttering rapidly and vibrating the air to make sound.

• The vibrating folds themselves also add their own “harmonic” frequencies to the voice.

Functions of the Larynx:

• Protect the airway: The vocal folds can close rapidly to prevent choking.
• Lets us build air pressure for effortful tasks.
• Controls flow of air in and out of the lungs.
• The source of sound.

On Aging:

The vocal folds are made of skin, gel, ligament, and muscle.

• Hydration affects the gel and is why voice quality changes throughout the day.
• With age, the gel layers and muscle fibers thin (atrophy).
  • Masculine voices age towards higher octaves.
  • Feminine voices age towards lower octaves.

Pitch

Pitch: The degree of highness or lowness in the perception of sound.

• Controlled by the speed the vocal folds are vibrating.
• Interrelated to resonance and expressive intonation.

Modal v.s. Average Pitch:

• Modal: Resting pitch, the pitch you return to.
• Average: The average pitch you’ve spoken in, changes with emotion / intonation.

Ballpark Ranges:

• Cis Male: 100—140 Hz
• Recommended Ranges for Trans Women: 165—196 Hz

Notes to start feminising pitch exercises:

• E3 (165 Hz)
• F3 (175 Hz)
• G3 (196 Hz)
• A3 (220 Hz) (rare)

Measuring Pitch

• Audio Spectruym Analyzer (Fdroid) is a good tool for measuring your pitch.
  • It’s also helpful to see the contour movement of your voice rising and falling (intonation), loudness, and modal pitch.
• Remember: Focus on the sound and feeling of your target pitch, don’t over-focus on the measurement.

On Surgery:

• A last resort for after you’ve achieved maximum gains from voice therapy.
  • Phonosurgery only affects pitch, which is only one facet of voice.
• Risks: Irreversible voice deepening, variable outcomes, deterioration in voice quality, loss of upper singing range, long-term pitch instability.

Intonation

Intonation: The movement of pitch, used for meaning-making.

• aka: inflection
• Changes with accent/dialect and culture.
• Highly individual.

C. Filter

Following the Path:

1. The vibrating air produced at the larynx travels up the vocal tract,
2. Gets amplified in the throat, and
3. Leaves through the pharynx (mouth/nose).

Formants: The natural resonance of the throat and pharynx modifies the fundamental sound.

• This is known as resonance and intensity (amplification), which gives the voice a richer tone (timbre).
• Affected by length of vocal tract and fine muscle control in the larynx and pharynx.

“If you pronounce it as tim-ber instead of tam-ber, I’m going to be disappointed.  — My music professor

On the Pharynx:

• Lowering the palate makes air enter the nasal cavity.
  • e.g., ‘m’, ‘n’, ‘ng’ (humming) sounds
• Raising the palate makes air enter the oral cavity.

Secondary Resonance: Occurs in the bones and muscles.

• Affected by physical makeup and habit.
• This affects the identity/style if a voice
  • e.g., ‘warmth’ caused how the speaker balances resonance.

Getting a Richer Sound:

• Any voice becomes richer when the sound resonates freely through the spaces in the body, which is also important for projecting the voice.
• Identifying and raising resonances in the mouth and head helps with voice feminization.
  • Higher and more forwards tongue position
  • Smaller jaw movements.

Articulation

Our moving articulators (tongue, soft palate, lips, jaw) interact with fixed ones (hard palate (roof of mouth), ridge behind teeth (aleovar ridge), and teeth).

Some studies suggest the women a perceived to speak with more precision and clearer articulation.

• Though, intelligibility is a key part of confident communication.