Phonation PDF

PHONATION Lecture 5 and 6 1. Describe the role of phonation in speech production - Role of Phonation in Speech Production: Phonation is the process of producing sound at the level of the larynx. - It forms the foundation of speech, as the vibrations of the vocal folds generate the...

PHONATION Lecture 5 and 6 1. Describe the role of phonation in speech production - Role of Phonation in Speech Production: Phonation is the process of producing sound at the level of the larynx. - It forms the foundation of speech, as the vibrations of the vocal folds generate the primary sound source. This sound is then shaped by articulation and resonance in the vocal tract to create intelligible speech. How is sound produced? - Sound in phonation is produced when air from the lungs passes through the glottis (the space between the vocal folds), causing the vocal folds to vibrate. This vibration generates a sound wave, which is modified by the vocal tract to form speech sounds. The process depends on the precise control of airflow and vocal fold tension What structures are involved in sound production? - Several key structures play roles in phonation: 1. Larynx: houses the vocal folds and is central to sound production. 2. Vocal Folds: Flexible, layered structures made of muscle and connective tissue that vibrate to produce sound. 3. Cricoarytenoid Joints: Allow vocal fold movement, including abduction and adduction. 4. Muscles of the Larynx: ○ Posterior Cricoarytenoid Muscles: Responsible for abduction (moving vocal folds apart). **responsible for abduction > ○ Lateral Cricoarytenoid and Arytenoid Muscles: Facilitate adduction (bringing vocal folds together). - Bringing the anterior ⅔ rds together - Bringing the posterior ⅓ together  ○ Cricothyroid Muscles: Control vocal fold lengthening and tension. ○ Thyroarytenoid Muscles: Adjust vocal fold contact and tension (shortens) - Medial compression How do vocal folds move? The movement of the vocal folds is dynamic and involves: 1. Abduction: Vocal folds move away from the midline, primarily due to the posterior cricoarytenoid muscles. 2. Adduction: Vocal folds move toward the midline, facilitated by the lateral cricoarytenoid and arytenoid muscles. 3. Length Change: ○ Lengthening occurs with cricothyroid muscle contraction. ○ Shortening happens through thyroarytenoid muscle contraction. 4. Vibratory Motion: Includes a "mucosal wave" as the folds open and close in a wavelike pattern. What makes a voice unique? A person’s voice is unique due to individual differences in: 1. Vocal Fold Structure: Thickness, length, and elasticity of the vocal folds influence pitch and tone. 2. Vocal Tract Configuration: Shape and size of the oral and pharyngeal cavities determine resonance and timbre 3. Phonation Dynamics: Variations in the force and coordination of vocal fold movements. 4. Habitual Use and Technique: Long-term vocal habits, health, and training shape voice quality. - These factors combine to create the distinctive timbre (refers to the unique tonal quality or color of a sound that distinguishes it from other sounds of the same pitch and loudness), pitch range, and resonance of each person’s voice 2. Identify 2 paired and 3 unpaired cartilages of the larynx. Unpaired 1. Epiglottis 2. Thyroid cartilage 3. Cricoid cartilage (ring) Paired 1. Arytenoid cartilages 2. Corniculate cartilages – mini pieces of corn that sit on top of the arytenoid cartilages 3. Explain the location, structure, and function of the hyoid bone. - Location: The hyoid bone is located in the neck, at the level of the third cervical vertebra (C3), between the lower jaw (mandible) and the larynx. It is suspended in place by a series of muscles and ligaments rather than being directly attached to any other bone, making it unique in the human skeleton (only floating bone) - Structure: The hyoid bone is a small, U-shaped bone consisting of: - Body: The central part of the bone. - Greater horns (greater cornua): Two larger, curved projections extending backward from the body. - Lesser horns (lesser cornua): Two smaller projections that extend upward from the junction of the body and greater horns. - It is composed of dense, compact bone and serves as an anchor point for muscles and ligaments - Function: - Support for the Tongue: The hyoid bone provides a base for the tongue muscles, assisting in tongue movement and positioning. - Facilitation of Swallowing and Speech: It acts as an attachment point for muscles of the pharynx, larynx, and tongue, playing a key role in swallowing and speech production. - Structural Stability: The hyoid helps maintain the open airway in the upper neck, contributing to respiratory and vocal functions.  4. Label and describe laryngeal joints, ligaments, and membranes. Larynx: Cricothyroid Joints - The cricoid and thyroid cartilages are attached via the anterior, lateral, and posterior ceratocricoid ligaments - The cricothyroid joint has two motions: Rotating (primary motion) Gliding Cricoarytenoid Joints - Cricoid and arytenoid cartilages are attached via the anterior and posterior cricoarytenoid ligaments. - Two motions: rocking of the arytenoid cartilage OR gliding of the arytenoid cartilage. Intrinsic Ligaments and Membranes - Intrinsic ligaments and membranes connect laryngeal cartilages to one another Ligaments: 1. Thyroepiglottic ligament: runs from thyroid cartilage to epiglottis  2. Ventricular ligament: thickened base of quadrangular membrane. Membranes - Conus Elasticus: connects cricoid, arytenoid and thyroid cartilages. Give rise to middle cricothyroid ligament, lateral cricothyroid membranes and vocal ligaments.  - Quadrangular membrane: Quadrangular membrane connects epiglottis, thyroid cartilage, arytenoid cartilages, and corniculate cartilages. Thickens at the bottom to become ventricular ligaments. Extrinsic ligaments and Membranes: Extrinsic ligaments and membranes connect laryngeal cartilages to outside structures Ligaments - Hyoepiglottic ligament: connect hyoid bone to epiglottis Membranes - Cricotracheal membrane: connects cricoid cartilage to tracheal rings - Hyothyroid membrane: connects the hyoid bone to thyroid cartilage and gives rise to the middle and lateral hypothyroid ligaments.  - Membranes are thin protective layers, often involved in secretion or lining cavities. - Ligaments connect bones and stabilize joints. (ligaments link bones) - Tendons attach muscles to bones and enable movement. (tendons tie muscle to bone) 5. Cavities and internal regions of the larynx and surrounding areas. Laryngeal Cavity: - Extends from bottom of the cricoid cartilage to the laryngeal aditus (the entrance of the cavity of the larynx) - Laryngeal aditus: comprises the tops of arytenoid (and corniculate) cartilages, sides of epiglottis, and aryepiglottic folds. - Aryepiglottic folds run between arytenoid cartilages and epiglottis and develop the aryepiglottic muscles and cuneiform cartilages - Upper region (laryngeal vestibule) is bounded by the ventricular folds below and laryngeal aditus above - Lower region is bounded by the cotton of the cricoid cartilage below and the vocal folds above. 5 layers of the vocal folds: 1. Epithelium: Squamous cells 2. Superficial Lamina Propria: A few elastic fibers 3. Intermediate Lamina Propria: many elastic fibers 4. Deep Lamina Propria: many collagen fibers 5. Muscle: Muscles fibers (thyrovocalis) Parts of the Vocal Folds: 1. Membranous part (anterior): lies between thyroid cartilage and tips of vocal processes of arytenoid cartilages; occupies 60% of length - Remember the lateral cricoarytenoid muscles adduct this portion 2. Cartilaginous part (posterior): lies between the vocal processes and most rearward point on the medial surface of arytenoid cartilages occupies 40% of length. - Remember the arytenoids close this portion Ventricular Folds - Sometimes called the false vocal folds - Contain ventricular ligaments and sparse muscle fibers - Contain mucous glands that secrete mucus to lubricate vocal folds Laryngeal Ventricles - Depression between the ventricular and true vocal folds - Contain mucous glands that secrete mucus to lubricate the vocal folds  6. Identify extrinsic, intrinsic, and supplemental musculature of the larynx. - Intrinsic muscles (both attachments inside the larynx) - Extrinsic muscles (one attachment inside the larynx and one outside the larynx) - Supplementary muscles (both attachments outside the larynx; actions influence the larynx through the hyoid bone) Intrinsic muscles Thyroarytenoid: Made up of the internal thyroarytenoid (thyrovocalis) and external thyroarytenoid (thyromuscularis). - Vocal cord = vocal ligament + thyrovocalis - Vocal fold = vocal ligament + thyrovocalis + thyromuscularis Posterior Cricoarytenoid: Contraction rocks arytenoid cartilage away from midline and may also slide it upward and backward. - The also abduct the vocal folds Lateral Cricoarytenoid: Contraction rocks the arytenoid cartilage toward the midline and may slide the arytenoid forward and toward the side. - They also adduct (move together) the anterior 2/3rds of the vocal folds  Lateral Cricoarytenoid Arytenoids (transverse and oblique) thyroarytenoid and thyrovocalis 1. What part of vocal folds are membranous? 2. What muscles close this portion? 3. What parts are cartilaginous? 4. What muscles close this portion? 5. What muscles cause full adduction of vocal folds? 6. Once closed fully… What muscles cause compression? 7. Can you have compression with configuration of small glottis at back? 8. What muscle swings the vocal folds up and out? Arytenoid: Two parts - ADDUCT (ADD TOGETHER) THE POSTERIOR 1/3 OF THE VOCAL FOLDS 1. Transverse Arytenoid: pulls arytenoid cartilages together. 2. Oblique arytenoid: pulls arytenoid cartilages toward each other in a tipping action ‘ Contraction of the aryepiglottic muscle pulls the epiglottis backward and downward to cover the larynx. - Protects the airway Cricothyroid - Two parts, contraction increases the distance between the upper border of the cricoid cartilage and the lower border of the thyroid cartilage at the front. - Primarily a rocking movement but also a forward sliding movement effected through the pars oblique. 1. Par Rectus 2. Pars Oblique Extrinsic laryngeal muscles Extrinsic muscles - Sternothyroid: Contraction pulls the thyroid cartilage downward. - Thyrohyoid: Contraction decreases the distance between the thyroid cartilage and hyoid bone. - Inferior Constrictor: Contraction moves the sidewall of the lower pharynx inward. Supplemental muscles of the larynx - Infra hyoid means it originates below the hyoid bone - Suprahyoid means it originates above the hyoid bone - Sternohyoid: contraction pulls downward on hyoid bone. - Omohyoid (shoulder to hyoid): Posterior belly and Anterior belly. Contraction pulls downward and backward on the hyoid bone. - Digastric: Contraction pulls the hyoid bone upward and forward or upward and backward. - Stylohyoid: Contraction pulls upward and backward on the hyoid bone. - Geniohyoid: contraction can pull upward and forward on the hyoid bone. - Hyoglossus: Contraction can pull up on the hyoid bone. - Genioglossus: contraction can pull the hyoid bone upward and forward.  7. Relate the movements of laryngeal anatomy to sound production. Phonation is the sound produced at the level of the larynx. Filter exists above the larynx to filter sound and create speech sounds. Abduction = movement of vocal folds away from midline. - Posterior cricoarytenoid muscles are the primary abductors. > Tracheal tug: downward pull on the conus elasticus. - Occurs due to the excessive effort required to breathe when there is an obstruction or significant resistance in the airways Adduction: movement of vocal folds toward midline. >>>