Recording-2025-04-15T19:57:21.624Z

Function of Lungs:
- Create an airstream that vibrates the vocal folds through the larynx.
- Vital for gas exchange, primarily oxygenating the blood.
Inhalation (Inspiratory Phase):
- For lungs to inflate, pressure inside them must be less than atmospheric pressure.
- Achieved by diaphragm contraction (pulling down) and interaction with rib muscles which enlarge the thoracic cavity.
Exhalation:
- Initially involves a quick inhalation followed by a longer exhalation when speaking.
- Inhale approximately 1,000 cc of air when engaged in speech breathing compared to around 100 cc during restful breathing.
- Use of abdominal muscles to control airflow and pressure vital for speech production.

Phonation:
- The production of voice; requires air to flow through the larynx, utilizing the vibration of the vocal folds.
Laryngeal Functions:
- Biological Function: Protects the airway (e.g., prevents food/water from entering lungs).
- Reflex actions such as coughing help to protect the airway.
Vocal Folds:
- Composed mostly of cartilage and muscle; they can be adducted (closed) or abducted (open).
- Mnemonic Aid:
- Adducted = ADD (together)
- Abducted = Abduction (apart).
Sound Production:
- Airflow causes the vocal folds to vibrate, creating sounds.
- Pitch changes based on the length of vocal folds: longer = higher pitch, shorter = lower pitch.

Frequency of Vibration:
- Measured in Hertz (Hz); e.g., 60 Hz for low sounds up to 3000 Hz for higher-pitched sounds.
- Voiced sounds (like vowels) engage vocal fold vibration, while voiceless (like /s/) do not.
Control of Vocal Folds:
- Ability to change tension influences the amount of air pressure needed for vibration.
- Tense vocal folds require more air to vibrate compared