Anatomy and Physiology of Speech and Hearing — Comprehensive Notes

Overview

  • Chapter focus: anatomy and physiology of speech and hearing; foundational concepts for understanding normal communication and disorders.
  • Objectives (after reading):
    • Identify major anatomical structures related to speech, language, and hearing.
    • Describe the physiological functions of these structures.
    • Name individuals who contributed to the understanding of speech and hearing anatomy.
    • Describe essential physiological processes involved in speech production.
    • Describe essential physiological processes involved in hearing.
    • Understand how impairments in one or more anatomical structures can contribute to a communication disorder.
  • Key terms introduced (glossary-style): Anatomy; Dissection; Physiology; Gross Anatomy; Cellular Anatomy and Physiology; Upper Respiratory Tract; Lower Respiratory Tract; Nasal Cavity; Cilia; Mouth; Breathing; Adenoids; Pharynx; Esophagus; Bronchial Tubes; Bronchitis; Bronchioles; Alveoli; Lungs; Rib Cage; Diaphragm; Respiratory Cycle; Inhalation Phase; Exhalation Phase; Active muscular process; Passive muscular process; Larynx; Thyroid Cartilage; Laryngeal Prominence; Epiglottis; Hyoid Bone; Cricoid Cartilage; Vocal Folds; Arytenoid Cartilages; Glottis; Phonation; Fundamental Frequency; Articulation; Vocal Tract; Oral Cavity; Pharyngeal Cavity; Movable Articulators; Lips; Ventriloquism; Tongue; Soft Palate; Uvula; Velopharyngeal Closure; Mandible; Pipe Speech; Fixed Articulators; Hard Palate; Alveolar Ridge; Teeth; S* T = P; Source Transfer Function; Laryngeal System; Articulatory System; Audition; Peripheral Auditory System; Central Auditory System; Auricle; Pinna; Helix; Tragus.
  • Introductory framing: Speech and hearing anatomy uses structures also employed for non-speech tasks (breathing, swallowing, coughing); anatomy/physiology knowledge foundational for audiology and speech-language pathology; material revisited in later chapters for disorders arising from anatomical/physiological abnormalities.

Anatomy and Physiology Foundations

  • Anatomy vs Physiology:
    • Anatomy: study of structure of the body and its parts; etymology from Greek ana (up/through) + tome (a cutting).
    • Physiology: study of function; etymology from physis (nature) + logia (to speak).
  • Dissection as historical method; modern living-body study uses noninvasive methods (endoscopy, CT, MRI).
  • Gross Anatomy vs Cellular Anatomy (histology):
    • Gross anatomy: structures visible to the naked eye.
    • Cellular anatomy/physiology: microscopic structures.
  • Why this is essential:
    • Understanding normal communication and disorders requires knowledge of structure and function of speech and hearing mechanisms.
  • Chapter scope:
    • Introductory exposure to speech and hearing anatomy/physiology.
    • Concepts referenced again in later chapters on disorders from anatomical/physiological abnormalities.

Speech Anatomy: Three Subsystems

  • The anatomy used to produce speech is the same as that used for nonspeech tasks (breathing, swallowing, coughing).
  • Three subsystems of speech anatomy:
    • (a) Respiratory System
    • (b) Laryngeal System
    • (c) Articulatory System
  • Purpose: Humans exploit these original survival-designed structures for communication.
  • Described survey of structure and function for each subsystem.

Respiratory System

  • Components: lungs, diaphragm, rib cage, trachea, pharynx, oral and nasal passages.
  • General location: Upper vs Lower respiratory tract (illustrative Figure 2–1 reference).
  • Two tracts:
    • Upper Respiratory Tract: includes oral cavity, nasal cavities, pharynx.
    • Lower Respiratory Tract: includes trachea, bronchi, lungs.
  • Air intake: Inhaled primarily through the nostrils into the nasal cavity.
  • Nasal cavity features: mucous membranes with tiny hairs called cilia.
    • Function (as described): warm the air (and humidify/ filter it in typical explanations).
  • Key path of air: nasal cavity → pharynx → larynx → trachea → bronchi → lungs (implied by tract division).

Laryngeal System (as part of Voice Production)

  • (Page 2 concepts listed under laryngeal components):
    • Thyroid Cartilage; Laryngeal Prominence; Epiglottis; Hyoid Bone; Cricoid Cartilage.
    • Vocal Folds; Arytenoid Cartilages; Glottis.
  • Phonation concepts:
    • Fundamental Frequency: often denoted as $F_0$; relates to pitch of voice.
  • Movements/structures underlying voice:
    • Laryngeal framework controls voicing via vocal fold vibration.
    • Epiglottis guards airway during swallowing; vocal folds and arytenoids adjust glottal opening.
  • Velopharyngeal considerations:
    • Velopharyngeal Closure; connection to nasal/oral cavity separation during speech.

Articulatory System

  • Components: Vocal Tract; Oral Cavity; Pharyngeal Cavity.
  • Movable articulators:
    • Lips; Tongue; Soft Palate; Uvula; Velopharyngeal Closure; Mandible.
    • Term “Pipe Speech” appears (context suggests analogy with air as a pipe channel).
  • Fixed articulators:
    • Hard Palate; Alveolar Ridge; Teeth.

Source, Transfer, and Auditory Systems

  • Source-Transfer framework concept (S*T = P):
    • Source (S) interacting with Transfer Function (T) producing output (P).
    • Notation:SimesT=PS imes T = P (Source × Transfer = Output).
  • Key subsystems for audition and speech production:
    • Laryngeal System (voice source)
    • Articulatory System (shape of vocal tract)
    • Audition (hearing) with subdivisions:
    • Peripheral Auditory System; Central Auditory System
  • Peripheral Auditory System components (outer/middle ear):
    • Auricle; Pinna; Helix; Tragus.
    • External Auditory Meatus; Temporal Bone; Cerumen; Tympanic Membrane.
    • Ossicular Chain: Malleus; Incus; Stapes.
    • Muscles: Tensor Tympani; Stapedius; Acoustic Reflex.
    • Eustachian Tube (connects middle ear with nasopharynx).
  • Vestibular apparatus involved in balance (not core to hearing).
  • Inner ear structures for hearing:
    • Cochlea; Semicircular Canals; Basal/Apical (of Cochlea) locations; Scala Vestibuli; Scala Tympani; Scala Media; Helicotrema.
    • Fluids: Perilymph (in Scala Vestibuli/Tympani); Endolymph (in Scala Media).
    • Organ of Corti; Hair Cells; Basilar Membrane; Tonotopic Organization (frequency mapping).
    • Auditory Nerve; Cochlear Nucleus; Brainstem Nuclei; Auditory Cortex.

Histories and Notable Figures (Historical Contributions)

  • Notable contributors named in the text:
    • Henry Gray; Henry Vandyke Carter; Bartolomeo Eustachi; Antoine Ferrein; Alfonso Corti; Albert von Kölliker; Anna Morandi Manzolini; Sir Victor Negus; Willard R. Zemlin.
  • Other related terms: Anthropometry; Alphonse Bertillon (noted in the list).
  • Purpose of naming figures: Recognize historical advances in anatomy/physiology that underpin modern understanding of speech and hearing.

Introduction to Concepts and Terminology

  • Core definitions reiterated:
    • Anatomy: study of body structure; from Greek terms indicating cutting through structures.
    • Physiology: study of function; from Greek terms indicating nature and study of speaking.
  • Normal anatomy/physiology foundations are essential for audiology and speech-language pathology training.
  • Modern methods for examining living bodies include endoscopy and imaging (CT, MRI).
  • Chapter emphasizes that the same anatomical structures used for basic survival tasks are repurposed for speech production.
  • Emphasis on the interdependence of respiratory, laryngeal, and articulatory subsystems for speech and voice production.

Practical and Real-World Relevance

  • Understanding the anatomy helps explain how impairments lead to communication disorders.
  • Knowledge supports assessment, diagnosis, and treatment planning in clinical practice (speech-language pathology and audiology).
  • The material lays groundwork for later chapters addressing disorders caused by structural or functional abnormalities of speech/hearing mechanisms.

Connections to Foundational Principles

  • Multidisciplinary basis: anatomy, physiology, acoustics, psychology, and neurology intersect in speech and hearing science.
  • The three-subsystem model (respiratory, laryngeal, articulatory) reflects an integrative view of speech production.
  • The auditory system’s structure-function relationship (peripheral vs central processing, tonotopic organization) underpins how we perceive speech and language.

Ethical, Philosophical, and Practical Implications

  • Ethical implications of medical imaging and dissection historically tied to anatomical study; modern noninvasive methods minimize risk.
  • Practical implication: interdisciplinary collaboration is essential for diagnosing and treating communication disorders.
  • Philosophical note: anatomy provides the substrate for human communication and identity; disruptions have broad social and quality-of-life impacts.

Equations, Numerical References, and Key Terms (LaTeX)

  • Source-Transfer function concept:
    • SimesT=PS imes T = P
  • Fundamental frequency (as a variable): F0F_0
  • The two tracts of the respiratory system: 22 tracts (Upper and Lower).
  • Notation and terminology used in the text:
    • Upper Respiratory Tract; Lower Respiratory Tract; Nasal Cavity; Cilia; Epiglottis; Vocal Folds; Glottis; Arytenoid Cartilages;
    • Phonation; Articulatory System; Movable Articulators; Fixed Articulators; Velopharyngeal Closure;
    • Organ of Corti; Basilar Membrane; Hair Cells; Tonotopic Organization; Cochlear Nerve; Auditory Cortex.

Figures and References in the Text

  • Figure reference: Figure 2–1 for the general location of respiratory structures.
  • Primary source material for these notes: Robb, Michael P. INTRO: a Guide to Communication Sciences and Disorders, Plural Publishing, Incorporated, 2023. ProQuest Ebook Central. Ebook pages 42-43; Printed page 1–4.

Summary Takeaways

  • Speech uses the same anatomy as other vital functions, organized into three subsystems: respiratory, laryngeal, articulatory.
  • The respiratory system provides the airflow and support for phonation and speech; it’s divided into upper and lower tracts.
  • The larynx houses the vocal folds and related cartilages; it governs voicing and airway protection.
  • The articulatory system shapes the speech stream via movable and fixed structures, forming distinct speech sounds.
  • Hearing relies on a complex peripheral and central auditory system, from the outer ear to the auditory cortex, organized tonotopically to encode frequency information.
  • Historical anatomists and scientists laid the groundwork for modern speech and hearing science, highlighting the long-standing interdisciplinary nature of the field.
  • The knowledge base developed here informs clinical practice and paves the way for understanding communication disorders arising from anatomical or physiological abnormalities.