1. Respiration (Breathing):
* Lungs: Provide the airflow necessary for speech.
* Diaphragm: The primary muscle of respiration, contracts and relaxes to draw air into and out of the lungs.
* Intercostal muscles: Help expand and contract the rib cage, supporting breathing.
2. Phonation (Voice Production):
* Larynx (voice box): Contains the vocal cords, which vibrate to create sound.
* Vocal cords: Two folds of tissue that stretch across the larynx. Air passing through them causes vibrations that produce sound waves.
* Pitch and loudness: The tension of the vocal cords determines the pitch (high or low) of the voice, while the amount of airflow determines loudness.
3. Articulation (Shaping Sound):
* Pharyngeal cavity: The space at the back of the mouth, helps shape the sound.
* Oral cavity (mouth): Contains the tongue, teeth, and hard palate, which move to modify the airflow and create different speech sounds.
* Nasal cavity: Contributes to some sounds, like the "m" and "n," by allowing air to pass through the nose.
How It Works:
1. Inhaling: Air is drawn into the lungs.
2. Exhaling: The diaphragm and intercostal muscles contract, pushing air out of the lungs.
3. Phonation: Air passes through the larynx, causing the vocal cords to vibrate, producing sound.
4. Articulation: The tongue, teeth, lips, and other articulators modify the airflow, creating different sounds.
Important Note: The speech mechanism is incredibly complex and involves the coordination of many different muscle groups and neurological processes. This allows for the production of a wide variety of sounds and languages.