Anatomy and Function of Vocal Tract Articulators

• The vocal tract's anatomy comprises several articulators crucial for speech production
• Articulators modify the vocal tract's shape, influencing the sound of speech

Mobile Articulators

• Tongue: Highly flexible, it shapes vowels and constricts consonants
• Mandible (Lower Jaw): Supports the tongue and lower lip, contributing to articulation
• Lips: Create constrictions and closures for sounds like /p/, /b/, and /m/, and shape vowels
• Velum (Soft Palate): Directs airflow through the nose or mouth by raising or lowering
• Vocal Folds: Vibrate to produce voiced sounds; located in the larynx

Immobile Articulators

• Alveolar Ridge: Gum ridge behind upper teeth; point of contact for sounds like /t/, /d/, /s/, and /z/
• Hard Palate: Bony roof of the mouth
• Upper Teeth: Important for producing sounds like /f/ and /v/

Vocal Tract Cavities

• Oral Cavity: Space inside the mouth, crucial for shaping many speech sounds
• Nasal Cavity: Responsible for nasal sounds, when the velum is lowered
• Pharyngeal Cavity: Throat space that contributes to resonance

Tongue Anatomy

• Tip: The most anterior portion, important for alveolar sounds
• Blade: Lies just below the alveolar ridge when at rest
• Dorsum: The body of the tongue, makes contact with the hard and soft palates
• Root: Connects to the hyoid bone

Lips

• Orbicularis Oris: Primary muscle encircling the mouth
• Responsible for lip rounding, protrusion, and closure

Velum

• Muscular valve that opens or closes the nasal cavity
• During speech, it usually elevates to block the nasal cavity, directing airflow through the oral cavity

Vocal Folds

• Located within the larynx
• Vibrate to produce voiced sounds
• Abduct (open) for voiceless sounds and breathing

Articulatory Movements and Sound Production

• Articulators' movement and positioning, create different vocal tract shapes
• Different shapes produce different resonant frequencies
• Resonant frequencies determine the sound of speech

Vowels

• Produced with a relatively open vocal tract
• Tongue position (height and backness) and lip rounding are key articulatory features

Consonants

• Produced with some degree of constriction in the vocal tract
• Place of articulation: Where the constriction occurs (e.g., lips, teeth, alveolar ridge)
• Manner of articulation: How the constriction is made (e.g., stop, fricative, nasal)
• Voicing: Whether the vocal folds are vibrating

Articulatory Phonetics

• Studies how articulators produce speech sounds
• Uses descriptions based on place, manner, and voicing to classify consonants
• Uses tongue height, tongue backness, and lip rounding to classify vowels

Clinical Relevance

• Understanding articulatory anatomy is crucial for diagnosing and treating speech disorders
• Speech therapists assess and treat articulation errors by targeting specific articulators
• Neurological conditions can affect articulatory control, impacting speech

Development of Articulation

• Infants learn to control their articulators gradually
• Early sounds are reflexive and related to basic needs (e.g., crying, sucking)
• Babbling is an important stage in which infants experiment with different sounds
• Articulatory skills develop over time, with mastery of all sounds typically achieved by early school age

Acoustic Phonetics

• Studies the acoustic properties of speech sounds
• Acoustic measurements can provide information about articulatory movements
• Spectrograms display frequency, intensity, and time, and are used to analyze speech sounds