DOC PREVIEW
UI CSD 3112 - Phonatory System Physiology Introduction

This preview shows page 1-2-3 out of 8 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Source TheoriesGalen (200 AD)Trachea central origin of voiceThought to act like flute or vibrating column of airDodart (1700)Laryn origin of voiceVocal folds change cavity size much like tongue and lips change pitch in whistlingFerrein (1740)Vocal folds vibrate in animalsVocal folds work like stringed instrument; movement of string vibrates airNo need for airstream.It is the vibration that causes air to move**Helmholts (1860)laryngeal sound source related to puffs of air escaping through glottisvalving of airstream produces soundit is the airflow moving that causes the vibrationMovement Theories2 basic theories(of how valving is accomplished)Neurochronaxic theoryMyoelastic-Aerodynamic theoryMovement Theories—Neurochronaxicaction potentials (neural impulses along a nerve) produce each separate period of glottal vibrationmotor units in vocalis muscle twitch on cycle‐by‐cycle basistherefore, frequency of vocal fold vibration dependent on rate of neural impulses delivered to laryngeal musculaturefaster the neural impulses, faster the vocal fold vibrationreasons this theory was discounted1. action potential firing rateaction potential cannot fire that fastsome frequencies may work but not the high frequencies from like for example baby voices2. vocal fold muscle fiber orientationthe vocalis muscle sending impulse to the vocal folds move lateral mediallythe action potential impulses run anterior posteriorally*the directions do not match3. recurrent laryngeal nerve lengthleft and right nervesleft is longer in length because it has to loop aroundIf I send impulses to both sides, one vocal fold will receive the impulse fasterVocal folds have to vibrate simultaneously4. Chest thumpIf sudden thump (compression) on the respiratory system (chest), the thoracic cage volume decreasesThe sudden increase in air pressure pulse moves up through the airway and increases fundamental frequency a tad bit=rise in frequency*the respiratory system (aerodynamics) shouldn’t affect it because it’s not neuro-related5. airflowthis shouldn’t matter with neurons firingbut, vocal folds won’t vibrate without airflowplus the air has to be moving outMovement Theory—Myoelastic-Aerodynamicvocal folds subject to well established aerodynamic and physical principles(tissue of the) vocal folds compressible (deformable) and elasticset into vibration by air stream from lungs and tracheaegressive (outgoing airflow) in contrast to ingressivefrequency of vibration dependent on length in relation to tension and masshow does changing characteristics of tissue interact with airflow to affect frequency of vibrating?The Vibratory Cyclefirst condition necessary for vibration is buildup of pressure below foldsneed to dam up pressureglottis closed to within 3 mm and Ps builds upwhile respiratory pressure is drivinguse of lateral cricoarytenoid to bring vocal processes togetheruse of interarytenoids to slide them togetheras Ps rises above Po, opening force developedPs= pressure (subglottal)Po= pressure oral (atmospheric)when this force exceeds elastic recoil resistance, vocal folds forced apart, releasing compressed air bursthas to overcome recoil resistance to blow apart vocal foldsas folds move further apart, outward flow of air dissipatesnew forces take over to move vocal folds back to adductedpositionmyoelasticityelastic recoilsimilar to recoil of lung‐thorax unitaerodynamic forcesBernoulli effectBernoulli Effectair flowing through system creates suction force perpendicular to movement of airgreater the flow rate, greater the suction forceE =KE + PEE = total energy (constant throughout system) KE = kinetic energy (energy of motion) PE = potential energy (energy of pressure in system)as KE increases, PE decreases (and visa versa)*If you blow between two sheets of paper while holding them up, a suction will be created inbetween them due to the pressure difference, bringing the two sheets togetherstationary wing has equal pressure forces acting on top and bottom surface of wingin moving wing, air must flow further over top surface than bottom surface, but in same amount of timetherefore, moves fasterresults in lower pressure acting ontop of wing than bottomupward movement of wing (lift)same principle, but in reverse, used in race carsfront and rear wing shaped like inverted plane wing air flowing across wings creates down forceinverted wings under car create pressure differencepressure difference creates downward force to suction car to the groundkeeps it from flipping over at high speeds or when turning cornersif a tube is constricted, air will flow faster through the constricted sectiontherefore, pressure in tube will be less at the constrictionGlottal Vibration Cycle-coronal cut-Note vertical phase difference between top and bottom of vocal folds-Wave of vibrationalso note that folds separate firstposteriorlymovement is posterior-anterioranterior posterior wave differencegives rise to acoustic spectrum(quality and output of vocal folds)CSD 3112 1st Edition Lecture 20 Outline of Last Lecture I. Extrinsic Musclesa. Suprahyoidi. Digastricii. Stylohyoidiii. Mylohyoidiv. Geniohyoidb. Infrahyoidi. Sternohyoidii. Omohyoidiii. Sternothyroidiv. ThyrohyoidII. Intrinsic Musclesa. Thyroarytenoidi. Vocalisii. Thyromuscularisb. Cricothyroidc. Posterior Cricoarytenoidd. Lateral Cricoarytenoide. InterarytenoidsIII. Vocal Fold HistologyOutline of Current Lecture IV. Phonatory Systema. PhonationV. Source Theoriesa. Galen b. Dodartc. Ferreind. HelmholtsVI. Movement Theoriesa. Neurochronaxicb. MyoelasticVII. Bernouli EffectVIII. Glottal Vibration CycleCurrent Lecture Phonatory System Physiology Part 1Phonatory SystemThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Primary biological role—protect lower airwayAlso, regulate airflow into and out of lungsAlso, generation of soundPhonation Any type of laryngeal sound production in speechConversion of potential energy of compressed air into kinetic energy of acoustic vibration Just the output of laryngeal (different from articulated sound) Source Theories- Galen (200 AD)o Trachea central origin of voiceo Thought to act like flute or vibrating column of air- Dodart (1700) o Laryn origin of voiceo Vocal folds change cavity size much like tongue and lips change pitch in whistling- Ferrein (1740) o Vocal folds vibrate in animalso Vocal folds work like stringed instrument;


View Full Document

UI CSD 3112 - Phonatory System Physiology Introduction

Documents in this Course
Load more
Download Phonatory System Physiology Introduction
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Phonatory System Physiology Introduction and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Phonatory System Physiology Introduction 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?