Anatomy of larynx
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Anatomy of larynx






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    Anatomy of larynx Anatomy of larynx Presentation Transcript

    • LARYNX IS SOUND GENERATOR; SOUNDS ARE EXTENSIVELY MODIFIED IN SPEECH AND SINGING BY RESONANCE OF PHARYNX, NASAL CAVITY, ORAL CAVITY oLARYNXLARYNX oCartilages connected byCartilages connected by omembranes and ligaments,membranes and ligaments, omoved by musclesmoved by muscles oFunctions: 1)Functions: 1) SoundSound oproductionproduction o2)2) Closure of RespiratoryClosure of Respiratory oSystem - allows increase inSystem - allows increase in oAbdominal PressureAbdominal Pressure olarynxlarynx otracheatrachea
    • Situated at the upper end of trachea Opposite 3rd – 6th cervical vertebrae (men) Higher in women and children 44 x 43 x 36 mm / 36 x 41 x 26 mm Infants – smaller, narrow lumen, funnel-shaped, higher, cartilages softer & collapse easily At puberty AP diameter in males doubles
    • The Anatomy of the Larynx oFigure 23.4Figure
    • I. LARYNX: CARTILAGES oA. THYROID CARTILAGEA. THYROID CARTILAGE –– Shield shapedShield shaped o- has Sup. & Inf. Horns from upper & lower edges- has Sup. & Inf. Horns from upper & lower edges oLaryngealLaryngeal oProminenceProminence oSup.Sup. oHornsHorns oInf.Inf. oHornsHorns o-- Inf. horns make synovial hinges joint with Cricoid Cartilage;Inf. horns make synovial hinges joint with Cricoid Cartilage; o- Laryngeal Prominence = Adam’s Apple, more prominent in- Laryngeal Prominence = Adam’s Apple, more prominent in omalesmales
    • Laryngeal cartilages THYROID CARTILAGE Shield like , longest Meet at midline – Thyroid notch ( angle 90 /120 degrees) Fused anterior border – laryngeal prominence Intrathyroid cartilage separates the 2 laminae in childhood Posteriorly the laminae diverge Superior and inferior cornua
    • Superior cornu – long, narrow, curves upwards, backwards and medially, lateral thyroid ligament attached to tip Inferior cornu – shorter, thicker, curves downwards & medially, oval articular facet Oblique line – from superior thyroid tubercle (anterior to root of superior horn ) to inferior thyroid tubercle (on lower border of lamina) > site of attachment of muscles
    • Inner aspect smooth, mucosa covered Thyroepiglottic ligament, vestibular and vocal ligaments, thyroarytenoid, thyroepiglottic & vocalis muscles Superior border – thyrohyoid ligament Inferior border – cricothyroid ligament
    • LARYNX: CARTILAGES oB.B. CRICOIDCRICOID ocompletecomplete oring ofring of ocartilage hascartilage has onarrow Arch ant.,narrow Arch ant., obroad Lamina post.broad Lamina post. oCricoid meansCricoid means oSignet RingSignet Ring oLamina ofLamina of ocricoidcricoid oArch ofArch of ocricoidcricoid oANT .VIEWANT .VIEW oPOST .VIEWPOST .VIEW
    • CRICOID CARTILAGE :- Only complete cartilaginous ring (signet) Forms most of the posterior wall of larynx Broad quadrilateral lamina posteriorly and narrow arch anteriorly Articular facet for inferior cornu at junction of arch and lamina Articular facets for arytenoids on lamina Vertical ridge on midline for attachment of longitudinal muscles of the oesophagus
    • LARYNX: CARTILAGES Arytenoid - 2 pyramidal shaped cartilages above lamina – have synovial joints with Cricoid permit Swivel = Rotate Sliding = Ab/Adduct D. Corniculate - nodules above arytenoids in aryepiglottic folds E. Cuneiform - rod shaped, above corniculate cartilages oCuneiformCuneiform oCorniculateCorniculate oArytenoidArytenoid
    • ARYTENOID CARTILAGES :- Placed on upper & lateral border of lamina Three sided pyramid Vocal process – vocal fold Muscular process – posterior & lateral cricoarytenoid Anterolateral surface – vestibular ligament, vocalis & lateral cricoarytenoid muscles Medial surface – mucosa covered
    • Apex – articulates with corniculate cartilage Posterior surface – covered by transverse arytenoid Base – concave, articular facet Synovial joint with lax capsular ligament Rotatory and medial & lateral gliding movement.
    • CORNICULATE (Wrisberg) – Small, conical Elastic fibrocartilage Synovial joint or fused with apices of arytenoid Situated in the aryepiglottic fold CUNEIFORM (Santorini) – Small, elongated Elastic fibrocartilage Lateral to corniculate
    • LARYNX: CARTILAGES oF. EPIGLOTTISF. EPIGLOTTIS o- leaf shaped- leaf shaped ocartilagecartilage oposterior to rootposterior to root oof tongueof tongue o- connected to- connected to obody of hyoidbody of hyoid oand post side ofand post side of othyroid cartilagethyroid cartilage oPOST. VIEWPOST. VIEW
    • EPIGLOTTIS :- Thin, leaf-like, elastic fibrocartilage Projects upward behind tongue & hyoid Narrow stalk attached below thyroid notch by thyroepiglottic ligament Upper part directed upwards & medially Superior margin free Sides attached to arytenoid catilage by aryepiglottic fold. tubercle in the lower part of posterior surface
    • Pits on cartilage – mucous glands Anterior surface – mucosa covered Median and lateral glossoepiglottic fold Hyoepiglottic ligament Pre-epiglottic space – between epiglottis & thyrohyoid membrane, fat filled space Neonates & infants – omega shaped, long, floppy
    • The Glottis oFigure 23.5a,Figure 23.5a, b
    • Calcification –  Elastic fibrocartilage – epiglottis, corniculate, cuneiform & apices of arytenoid – not calcified  Hyaline cartilage – calcification by late teens / early twenties  Thyroid – starts at inferior cornu, rim is calcified leaving a translucent window till old age  Calcification of posterior part of lamina & arytenoid  Arytenoid – body & muscular process – 4th decade, vocal process not calcified
    • Ligaments of the larynx Extrinsic ligaments – Connect cartilages to hyoid and trachea Thyrohyoid Membrane :- Between upper border of thyroid & upper border of posterior surface of body and greater cornu of hyoid Fibroelastic tissue – condensed anteriorly to form median thyrohyoid ligament & posteriorly lateral thyrohyoid ligaments Cartilago triticea – small nodule Pierced by internal branch of superior laryngeal nerve & superior laryngeal vessels
    • Intrinsic ligaments Connect the cartilages to each other. Internal framework Quadrilateral Membrane :- Border of epiglottis and arytenoid cartilage Upper margin forms framework of aryepiglottic fold Lower margin – vestibular ligament which underlies the vestibular fold or false cords
    • Cricotracheal ligament – lower border of cricoid to 1st tracheal ring Hyoepiglottic ligament – epiglottis to back of body of hyoid
    • Conus Elasticus:- Cricovocal ligament Attached below to the upper border of cricoid cartilage Above between midpoint of laryngeal prominence to vocal process of arytenoid Free upper border forms vocal ligament , framework of vocal fold / true cord Anteriorly thickened to form cricothyroid ligament
    • II. LIGAMENTS OF LARYNX o1. Thyrohyoid Membrane1. Thyrohyoid Membrane olinks larynx to hyoid;links larynx to hyoid; oMedian ThyrohyoidMedian Thyrohyoid oLigament - thickenedLigament - thickened omidline partmidline part o2. Cricothyroid Membrane2. Cricothyroid Membrane olinks thyroid to cricoid;links thyroid to cricoid; oMedian CricothyroidMedian Cricothyroid oLigament - thickenedLigament - thickened omidline partmidline part o3. Cricotracheal ligament3. Cricotracheal ligament olinks Cricoid to firstlinks Cricoid to first otracheal cartilagetracheal cartilage oMedianMedian oThyrohyoidThyrohyoid oLigamentLigament oMedianMedian oCricothyroidCricothyroid oLigamentLigament
    • STRUCTURAL LIGAMENTS oEpiglottisEpiglottis o4. Quadrangular4. Quadrangular oMembraneMembrane linkslinks oArytenoidArytenoid oTo epiglottisTo epiglottisoArytenoidArytenoid
    • STRUCTURAL LIGAMENTS oEpiglottisEpiglottis oArytenoidArytenoid ocartilagecartilage oAryepiglotticAryepiglottic oFolds - overlieFolds - overlie oQuadrangularQuadrangular omembranemembrane
    • STRUCTURAL LIGAMENTS o5. Thyroepiglottic5. Thyroepiglottic oLigamentLigament olinks epiglottis tolinks epiglottis to othyroid cartilagethyroid cartilage oNOSENOSE oSUPERIORSUPERIOR oVIEWVIEW oABOVEABOVE oLARYNXLARYNX
    • STRUCTURAL LIGAMENTS oLower freeLower free oedge ofedge of oQuadrangularQuadrangular omembrane ismembrane is oCalledCalled oVestibularVestibular oLigament; deepLigament; deep oto Vestibularto Vestibular o(False Vocal)(False Vocal) oFoldsFolds oCORONALCORONAL oSECTIONSECTION oTHROUGHTHROUGH oLARYNXLARYNX otracheatrachea
    • B. FUNCTIONAL LIGAMENTS oFunctional ligaments:Functional ligaments: oConus ElasticusConus Elasticus -- oVibrating lips that ariseVibrating lips that arise ofrom entire upper edge offrom entire upper edge of oarch of cricoidarch of cricoid oAttach: ant. to Thyroid,Attach: ant. to Thyroid, opost. to Arytenoidpost. to Arytenoid oRima Glottidis -Rima Glottidis - oOpening BetweenOpening Between oVocal ligamentsVocal ligaments oVocalVocal oLigaments -Ligaments - oUpper freeUpper free oEdgesEdges oDeep toDeep to oVocalVocal oFoldsFolds oNOSENOSE
    • FUNCTIONAL LIGAMENTS o(In Coronal Section)(In Coronal Section) oConus ElasticusConus Elasticus oFunctionsFunctions o1) Sound Production – Vibrate1) Sound Production – Vibrate olike lips of trumpet player;like lips of trumpet player; o2) Close Rima Glottidis stops2) Close Rima Glottidis stops ooutflow air, upward movement ofoutflow air, upward movement of odiaphragm - when contractdiaphragm - when contract oabdominal muscle pressureabdominal muscle pressure oincreases in abdominal cavity;increases in abdominal cavity; ooccurs in childbirth, defecationoccurs in childbirth, defecation
    • III. MUSCLES OF LARYNX  A. Extrinsic muscles (ex. hyoid muscles) {joins the larynx to other structures} –  Move whole larynx as in swallowing 1) changes tension in vocal cords. 2)change in pitch:- increase in tension>> raises pitch.  B.intrinsic muscles { connecting the laryngeal cartilages}  1)decreased tension lowers pitch  2) open & close Rima Glottidis o1) CRICOTHYROID M. -1) CRICOTHYROID M. - oTensesTenses oVocal LigamentVocal Ligament oIncreasing PitchIncreasing Pitch oSlackSlack oTenseTense
    • Intrinsic muscles and extrinsic muscles All the Intrinsic muscles of the larynx are paired except tranverse inter arytenoid muscle. These are: 1)abductors of vocal cords=posterior crico-arytenoid. 2)adductors of vocal cords=lateral crico- arytenoid,interarytenoid,thyroarytenoid,cricothyroid. 3)tensors & adductors of vocal cords=cricothyroid,vocalis & thyro-arytenoid. 4)openers of the laryngeal inlet=thyroepiglottic 5)closers of the laryngeal inlet=interarytenoid & aryepiglottic.   Extrinsic muscles These are divided into two groups: 1)cervical muscles: A)suprahyoid muscles,which act as elevators of the larynx B)infrahyoid muscles(strap muscles),which acts as depressors of the larynx. 2)pharyngeal muscles including the inferior constrictor muscle.
    • MUSCLES OF LARYNX o5) ARYEPIGLOTTIC5) ARYEPIGLOTTIC oMUSCLEMUSCLE oPulls epiglottis downPulls epiglottis down oduringduring oswallowingswallowing o- Covers inlet to larynx- Covers inlet to larynx o- Not necessary in- Not necessary in oadult humansadult humans
    • MUSCLES OF LARYNX o2)THYROARYTENOID2)THYROARYTENOID oMUSCLE -MUSCLE - oRelaxesRelaxes oVocal LigamentsVocal Ligaments oDecreases pitchDecreases pitch oNOSENOSE
    • MUSCLES OF LARYNX o5) ARYTENOID5) ARYTENOID o(Transverse and(Transverse and ooblique arytenoid) -oblique arytenoid) - oAdduct vocal foldsAdduct vocal folds o4) LATERAL CRICOARYTENOID4) LATERAL CRICOARYTENOID o- Adduct- Adduct ovocal foldsvocal folds o3) POSTERIOR3) POSTERIOR CRICOARYTENOIDCRICOARYTENOID o–– AbductsAbducts ovocal foldvocal fold oAdduct closes rima glottidisAdduct closes rima glottidis oAbduct opens rima glottidisAbduct opens rima glottidis oArytenoidsArytenoids oCan rotate/slideCan rotate/
    • Cavity of the larynx Divided by vestibular & vocal folds into 3 compartments oSuperior vestibule oVentricle / sinus of the larynx oSubglottic space
    • Pre-epiglottic space (Space of Boyer) :- • Anterior – thyrohyoid ligament & hyoid • Posterior – epiglottis • Superior – hyoepiglottic ligament • Lateral – continuous with paraglottic space Para-glottic space:- • Lateral – thyroid cartilage • Medial – conus elasticus & quadrangular membrane • Posterior – anterior reflection of PFS mucosa
    • LARYNGEAL VENTRICLE Laryngeal sinus Elongated recess between vestibular & vocal folds Opens through a narrow slit into middle segment of larynx From anterior part a pouch extends between vestibular folds & inner surface of thyroid cartilage - saccule Mucous membrane lining the saccule contains numerous mucous glands
    • Respiratory System Organization oFigure 15-4(a)Figure 15-4(a) The Anatomy of the Larynx and Vocal Cords
    • LARYNGOSCOPE VIEW OF LARYNX oAnt.Ant. oTongueTongue oVocal FoldsVocal Folds o(true vocal(true vocal ofolds)folds) oEpiglottisEpiglottis oPost.Post. oVestibularVestibular FoldsFolds o(false vocal(false vocal ofolds)folds) ovocal foldsvocal folds oadducted whenadducted when otalking or singingtalking or singing
    • Vestibular folds Thick, pink folds of mucous membrane Encloses the vestibular ligament Anterior attachment is to angle of thyroid cartilage, inferior to epiglottis Posterior attachment to anterolateral surface of arytenoid cartilage superior to vocal process
    • Vocal fold Extends from the middle of angle of the thyroid cartilage to vocal process of arytenoid cartilage Layered structure – mucosa & muscle Mucosa – epithelium : stratified squamous Lamina propria – superficial, intermediate and deep layers Superficial – loose fibrous substance : Reinke’s space – vibrates maximum during phonation
    • Intermediate layer – elastic fibres Deep layer – collagenous fibres Intermediate & deep layers form vocal ligament Deep to vocal ligament – vocalis muscle Anterior and posterior macula flava protect vocal fold from damage due to vibration
    • TERMS ASSOCIATED WITH LARYNX oVESTIBULEVESTIBULE - inlet above false- inlet above false ovocal foldsvocal folds oVESTIBULAR (FALSE VOCAL)VESTIBULAR (FALSE VOCAL) oFOLDSFOLDS - overlie vestibular- overlie vestibular oligamentsligaments oVENTRICLEVENTRICLE - area between true- area between true oand false vocal folds; lateraland false vocal folds; lateral oextension is Laryngealextension is Laryngeal oSinusSinus oVOCAL (TRUE VOCAL) FOLDSVOCAL (TRUE VOCAL) FOLDS o- overlie vocal ligaments- overlie vocal ligaments oNOSENOSE
    • TERMS ASSOCIATED WITH LARYNX oARYEPIGLOTTICARYEPIGLOTTIC oFOLDSFOLDS - Overlie- Overlie oUpper Edge ofUpper Edge of oQuadrangularQuadrangular omembranemembrane oPiriformPiriform oRecessRecess - lateral- lateral oto laryngeal inletto laryngeal inlet
    • TERMS ASSOCIATED WITH LARYNX oVALLECULAEVALLECULAE o-depressions (2)-depressions (2) oBetween Med & LatBetween Med & Lat oGlossoepiglotticGlossoepiglottic oFoldsFolds o-Food/objects-Food/objects oLodge inLodge in oValleculaeValleculae oValleculaVallecula oMedialMedial oGlossoepiglotticGlossoepiglottic ofoldfold oLateralLateral oGlosso-Glosso- oEpiglotticEpiglottic
    • Mucous membranes of the larynx Closely attached over the posterior surface of the epiglottis, corniculate, cuneiform & vocal ligament Loosely attached elsewhere – swollen Epithelium – squamous / ciliated columnar or transitional Numerous mucous glands except at the vocal folds ( mucous from saccule ) Few taste buds on posterior surface of epiglottis and AEF
    • Multilayered vibrator Cover – epithelium and superficial layer of lamina propria Transition – intermediate & deep layer Body – vocalis muscle Blood vessels run parallel to the edge
    • V. NERVES OF LARYNX – Branches of Vagus oA. Superior Laryngeal N.A. Superior Laryngeal N. odivides to -divides to - o1. Internal Laryngeal N.1. Internal Laryngeal N. oGVA Sensory to LarynxGVA Sensory to Larynx oAboveAbove True Vocal FoldsTrue Vocal Folds o2. External Laryngeal N.2. External Laryngeal N. oSVE Motor to CricothyroidSVE Motor to Cricothyroid oB. Recurrent Laryngeal N.B. Recurrent Laryngeal N. o- GVA Sensory to Larynx- GVA Sensory to Larynx oBelowBelow True Vocal FoldsTrue Vocal Folds o- SVE motor to all other- SVE motor to all other oMuscles of LarynxMuscles of Larynx oGVA=GENERAL VISCERAL AFFERENTGVA=GENERAL VISCERAL AFFERENT oSVE=SPECIAL VISCERAL EFFERENTSVE=SPECIAL VISCERAL EFFERENT oSUP. LARYNG. NSUP. LARYNG. N oInt. Laryng. N.Int. Laryng. N. oExt. Laryng. N.Ext. Laryng. N. oRECURRENTRECURRENT oLARYNG. N.LARYNG. N.
    • Nerve supply Vagus – superior laryngeal nerve - Recurrent laryngeal nerve Superior laryngeal arises from the inferior ganglion of the vagus + br. from superior cervical sympathetic ganglion At level of greater horn of the hyoid divides into external & internal branches External > cricothyroid Internal > pierces thyrohyoid membrane
    • Divides into upper & lower branches > pierces inferior constrictor > unites with ascending branch of recurrent laryngeal nerve ( Galen’s anastomosis ) Recurrent laryngeal nerve – Right – loops around right subclavian artery Left – Loops around the aortic arch & ligamentum arteriosum Ascends in the tracheo-esophageal groove
    • Enters the larynx behind cricotracheal joint Divides into motor & sensory branch Motor – all intrinsic muscles of larynx except cricothyroid Sensory – below the level of vocal folds
    • VI. LARYNX - ARTERIAL SUPPLY oSup. Laryngeal A.Sup. Laryngeal A. ofrom Sup. Thyroidfrom Sup. Thyroid oarteryartery oInf. Laryngeal A.Inf. Laryngeal A. ofrom Inf. Thyroidfrom Inf. Thyroid oarteryartery
    • Blood supply Laryngeal branch of superior thyroid (br. of external carotid) Laryngeal branch of inferior thyroid (br. of thyrocervical trunk of 1st part of subclavian) Cricothyroid branch of superior thyroid Superior & middle thyroid vein, facial vein > internal jugular Inferior thyroid vein > brachiocephalic veins
    • VII. LARYNX - LYMPHATICS oSuperior DeepSuperior Deep oCervical NodesCervical Nodes oLarynx above trueLarynx above true ovocal foldsvocal folds oInferior DeepInferior Deep oCervical Nodes-Cervical Nodes- oLarynx below trueLarynx below true ovocal foldsvocal folds oVII.VII. oNote: Mucosa Tightly Attached to vocal foldsNote: Mucosa Tightly Attached to vocal folds oAnaphylactic Shock Swell Vestibular folds --SuffocationAnaphylactic Shock Swell Vestibular folds --Suffocation
    • Lymphatic drainage Separated by vocal fold into upper and lower group Above vocal fold -> upper deep cervical nodes Below vocal fold -> prelaryngeal, pretracheal & lower deep cervical Vocal folds firmly bound down to vocal ligament -> relative absence of lymphatics
    • VIII. OBSTRUCTION OF LARYNX: TRACHEOTOMY  open airway to lungs below obstructed larynx oTracheotomyTracheotomy o- cut between- cut between o1st & 2nd or 2nd –1st & 2nd or 2nd – o3rd Tracheal3rd Tracheal ocartilagescartilages
    • BLEEDING IS PROBLEM: MIDLINE THYROID VEINS o1) Sup. Thyroid vein1) Sup. Thyroid vein ofollows arteryfollows artery o2) Middle Thyroid2) Middle Thyroid ovein- to Int Jugularvein- to Int Jugular o3) Inf. Thyroid vein3) Inf. Thyroid vein oBoth sides join atBoth sides join at omidline -> L.midline -> L. oBrachiocephalic VeinBrachiocephalic Vein
    • OBSTRUCTION OF LARYNX: CRICOTHYROTOMY oCrico-Crico- oThyrotomyThyrotomy oLittle bleedingLittle bleeding oCricothyroid MembraneCricothyroid Membrane oOBSTRUCTIONOBSTRUCTION
    • onasal tractnasal tract o(hard) palate(hard) palate ooral tractoral tract ovelum (soft palate)velum (soft palate) ovelic portvelic port otonguetongue otongue tiptongue tip opharynxpharynx oglottisglottis (vocal folds and(vocal folds and space between vocal cords)space between vocal cords) ovocal folds (larynx)vocal folds (larynx) o= vocal cords= vocal cords oalveolar ridgealveolar ridge olipslips oteethteeth oThe Speech Production ApparatusThe Speech Production Apparatus (from Olive, p. 23)(from Olive, p. 23) oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o
    •  Acoustic Phonetics: Anatomy   Breathing and Speech • Duration of expiration in soft speech is 2.4 to 3.5 seconds; maximum value (singers, orators) is 15 to 20 seconds without distress. • Louder voice requires inhaling more deeply after expiration; also deeper inhalation if followed by longer speech. • More intense voicing requires greater lung pressure. • Lung pressure relatively constant throughout an utterance. • Emphasis in speech: greater tenseness in vocal folds yielding higher F0; greater lung pressure increases airflow (energy).
    • oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o o othethe false vocal foldsfalse vocal folds narrow thenarrow the oglottis during swallowing, preventingglottis during swallowing, preventing opieces of food from getting into thepieces of food from getting into the otrachea.trachea.
    • oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o oPhonationPhonation o oPhonation is “conversion of potential energy of compressed airPhonation is “conversion of potential energy of compressed air ointo kinetic energy of acoustic vibration.”into kinetic energy of acoustic vibration.” o oFor voiced speech:For voiced speech: o o1.1. Buildup of Pressure:Buildup of Pressure: o air pressure from the lungs pushes against closed vocal foldsair pressure from the lungs pushes against closed vocal folds o so that Pso that Psubglottalsubglottal > P> Poraloral; buildup continues until; buildup continues until o until Puntil Psubglottalsubglottal – P– Poraloral > elastic recoil force of vocal folds> elastic recoil force of vocal folds o2.2. Release:Release: o vocal folds forced open by pressure difference;vocal folds forced open by pressure difference; o burst of compressed air hits air in vocal tract, causingburst of compressed air hits air in vocal tract, causing o acoustic shock wave moving along vocal tractacoustic shock wave moving along vocal tract o
    • o Acoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o o Implications:Implications: 1.1. vocal folds do not open and close because of separate musclevocal folds do not open and close because of separate muscle o movementsmovements o 2.2. opening and closing is automatic as long as the resting positionopening and closing is automatic as long as the resting position o of the vocal folds is (near) closure, and there is sufficientof the vocal folds is (near) closure, and there is sufficient o pressure buildup below vocal foldspressure buildup below vocal folds o 3.3. Factors governing vocal fold vibration:Factors governing vocal fold vibration: o (a) position of vocal folds (degree of closeness between folds)(a) position of vocal folds (degree of closeness between folds) o (b) elasticity of vocal folds, depending on position and(b) elasticity of vocal folds, depending on position and o degree of tensiondegree of tension o (c) degree of pressure drop across vocal folds(c) degree of pressure drop across vocal folds
    • oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o oTypes of phonationTypes of phonation o oquietquiet obreathingbreathing oforcedforced oinhalationinhalation onormalnormal ophonationphonation owhisperwhisper
    • oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o oThe cycle of glottal vibrationThe cycle of glottal vibration o o1. folds at rest1. folds at rest o2. muscle2. muscle o contractioncontraction o3. increase in3. increase in o pressurepressure o4. forcing folds4. forcing folds o apartapart o5. “explosion”5. “explosion” o openopen o6. acoustic6. acoustic o shockwaveshockwave o8. folds close,8. folds close, o goto stepgoto step (3)(3) o7. rebound toward7. rebound toward o closureclosure
    • oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o oThe cycle of glottal vibrationThe cycle of glottal vibration oclosure to opening, 0 to 2.1closure to opening, 0 to 2.1 msecmsec oopening to closure, 2.4 to 4.5 msecopening to closure, 2.4 to 4.5 msec o((FF00 = 222 Hz)= 222 Hz)
    • oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o oTypes of phonationTypes of phonation o ovoiceless, whisper, breathyvoiceless, whisper, breathy ovoiced, creak, glottal stopvoiced, creak, glottal stop
    • oAcoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o oThe effects of nasalization on vowelsThe effects of nasalization on vowels o oFigure 4-17. An example of theFigure 4-17. An example of the oeffects of vowel nasalization oneffects of vowel nasalization on othe vowel spectrum. The spectrumthe vowel spectrum. The spectrum oenvelopes of a normal [a] and a heavilyenvelopes of a normal [a] and a heavily onasalized [a] were plotted… The firstnasalized [a] were plotted… The first othree formants are labeled in thethree formants are labeled in the onormal vowel. In the nasalized vowel,normal vowel. In the nasalized vowel, othere are three local reductions inthere are three local reductions in ospectrum level, indicated by “z’s”;spectrum level, indicated by “z’s”; othese are the result of the additionthese are the result of the addition oof anti-resonant zeros to the vocalof anti-resonant zeros to the vocal otract response, due to a wide-opentract response, due to a wide-open ovelar port.velar port.
    • o Acoustic Phonetics: AnatomyAcoustic Phonetics: Anatomy o o The effects of nasalization on vowelsThe effects of nasalization on vowels o Coupling of the oral and nasal tract introduces pole-zero pairsCoupling of the oral and nasal tract introduces pole-zero pairs o (resonances & anti-resonances, occurring in pairs) in the spectrum.(resonances & anti-resonances, occurring in pairs) in the spectrum. o The amount of coupling affects the spacing between each poleThe amount of coupling affects the spacing between each pole o and its corresponding zero, as well as their frequency locations.and its corresponding zero, as well as their frequency locations. 1.1. The presence of a pole-zero pair increases the apparent bandwidthThe presence of a pole-zero pair increases the apparent bandwidth of the neighboring formants.of the neighboring formants. 2.2. The presence of spectral zero below F1 tends to make the locationThe presence of spectral zero below F1 tends to make the location of F1 appear slightly higher (50-100 Hz) than it normally wouldof F1 appear slightly higher (50-100 Hz) than it normally would 3.3. If the zero is higher in frequency than its corresponding pole, the netIf the zero is higher in frequency than its corresponding pole, the net effect is to reduce the amplitude of higher frequencieseffect is to reduce the amplitude of higher frequencies o
    • Phonation Adduction of vocal folds & adduction and medial rotation of arytenoids Vocal folds are lengthened Changes in length & tension control pitch Tension in the vocal fold, decrease in subglottic air pressure & sucking-in-effect of escaping air bring the vocal folds together
    • Air from subglottis released in small puffs Vocal folds thinner at high pitch Mucosal wave travels from inferior to superior surface Sound produced is modified by resonating chambers above & below the larynx Converted to phonemes by articulation of pharynx, tongue, palate, teeth & lips