speech production

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Physiology of Speech ProductionDr Sisha Liz : 

Physiology of Speech ProductionDr Sisha Liz Pictures from body works

Systems : 

Systems Respiratory System Laryngeal System Articulatory System Nervous system

speech : 

speech Speech is an overlaid function uses systems that are have other primary functions

Speech production-aerodynamic theory : 

Speech production-aerodynamic theory Air column of sufficient pressure and duration Approximation of vocal cords Fundamental tone produced by passive vibration of vocal cords Cadaveric larynx Tracheostome

Respiratory System : 

Respiratory System The cycle of respiration: When the lungs expand to take air in, pressure within lungs drops below atmospheric pressure. Through the open laryngeal structure, the air moves into lungs and equalizes the pressure. The production of speech needs a supply of moving air that can set vocal folds in motion. Respiration provides this air supply. We speak on exhalation, while rapid and continuous adjustments of breathing are being made during speech.

Neurochronaxic theory : 

Neurochronaxic theory Central generation of recurrent nerve impulses Active contraction of thyroarytenoid muscle No longer considered

Cntd.. : 

Cntd.. High speed endoscopic studies Cyclic horizontal displacement of the folds as subglottic pressure pushed the cords laterally Elastic recoil again increases the subglottic pressure.

Vibration : 

Vibration Passive effects of subglottic pressure Physical properties of vocal cords Mechanical stress caused by extrinsic laryngeal musculature.

Contd.. : 

Contd.. Vocal folds exhibit vertical modulations in the contact mucosa Mucosal wave- 0.5-1m/sec Moves from inferior to superior margin Small changes in the mass,density or shape of vocal cord elicit marked change in the quality of voice

Quality of voice : 

Quality of voice Biomechanical properties of vocal cords Thyroarytenoid and vocalis tension and elasticity Subglottic pressure Glottic air particle velocity

Stiffness of vocal cord : 

Stiffness of vocal cord Epithelium and superficial layer of lamina propria-low stiffness-cover Intermediate and deep layers of lamina propria-transition Vocalis muscle-stiffest-body

Phonation : 

Phonation Phonation- (voice production) Vocal folds close. Air from lungs blows folds open. Vocal folds flap back and forth (zipper-like action) during sound production and create vibration or “buzz” which passes through vocal tract to modify/resonate sound (through pharynx and nasal or oral cavity and articulators) and produces the sound we hear. (SOURCE/FILTER THEORY)

Pitch : 

Pitch Muscles can also cause fold to shorten and lengthen which effects pitch Thin-quick thick-slower size and mass effects Pitchthe perceptual correlate of frequency of vibration. Frequency # or cycles per minute expressed in units called hertz (Hz) Cycle of vibration one sequence of vocal fold vibration The more cycles per second, the greater the increase in the pitch.

Frequency/Pitch : 

Frequency/Pitch Adult male: Average fundamental frequency of 110 Hz (110 cycles of vibration). Adult female: Average fundamental frequency of 225 Hz. Pitch or fundamental frequency also rises and falls during speech

Loudness : 

Loudness Loudness or intensityaerodynamic correlate is variation in subglottal air pressure. Laryngeal muscles contract to bring the vocal folds together more tightly With greater force adducting the folds, the more subglottal air it takes to blow them apart = greater intensity.

Articulatory System : 

Articulatory System Used for: Speech Chewing Swallowing Conditioning of inspired air

Articulators : 

Articulators Moveable & immobile structures used to produce the sounds of speech. Lips (upper & lower) for swallowing & articulation Jaw (mandible) raises/losers for articulation Tongue-used for articulation and swallowing Pharyngeal walls Soft palate Teeth-chewing, biting, articulation

Articulatory System : 

Articulatory System Sound (buzz from vocal folds) resonates through oral and nasal cavity and is shaped by the articulators to produce the speech sounds we hear. Lips Hard Palate Tongue Alveolar Ridge Teeth Velum (soft palate)

Contd…. : 

Contd…. Vocal cords are vibrating when air flow is diverted voiced consonants like b,d,g,m,n,w,v,z,l,and r are produced If not vibrating –non voiced consonants are produced-p,t,k,f,s… The consonants m,n,l,r and vowel sounds have no unvoiced cognates except when speech is entirely whispered.

Contd… : 

Contd… Role of auditory system Harmonic overtones predominate over non harmonic ones Pharyngeal proprioceptive mechanisms with connections to CNS.

. : 

. Thank u

The Nervous System : 

The Nervous System Two parts CNS Brain and spinal cord PNS Other nerves connect to brain and spinal cord

CNS : 

CNS Brain Cerebrum Higher level function Cerebellum Balance Left Hemisphere Language Right Hemisphere Music, Spatial Separated by Corpus Callosum

Four Lobes : 

Four Lobes Brain http://faculty.washington.edu/chudler/color/pic3.html Try and label them!

Frontal : 

Frontal Functions planning reasoning emotion attention judgment Primary motor cortex Plan speech and movements with cerebellum

Parietal : 

Parietal Primary sensory cortex Touch Temperature Pressure Pain

Occipital : 

Occipital Receive and process visual info

Temporal : 

Temporal Process hearing Language comprehension Memory Primary auditory cortex Hear speech and process it

Parts for S & L : 

Parts for S & L Most people process language in the left hemisphere Broca’s area Left frontal lobe Expressive language Wernicke’s area Post. Left temporal lobe Language comprehension

Brainstem and Spinal Cord : 

Brainstem and Spinal Cord Brainstem and spinal cord Pathway for sensory info to brain Brain to send motor info through

PNS : 

PNS Peripheral nervous system To and from body 12 pairs of Cranial Nerves To and from brain and brain stem 31 pairs of Spinal Nerves To and from spinal cord Anterior side of the cord- motor Posterior side- sensory Some reflexes handled at the spinal cord Hot hand

Respiratory system : 

Respiratory system Fcn: exchange of CO2 for O2 Body cannot store it so you have to breathe 12-18 cycles per min. Inhale and exhale = 1 cycle

Slide 33: 

The lungs: the organ of respiration The trachea: forms upper airway with mouth, nose, and upper throat. Tube of 20 cartilaginous rings transporting air into and out of the lungs. Bronchial tubes: two tubes that divide from the trachea, one to each lobe of the lungs. These further divide into bronchioles to alveolar ducts to alveoli where gas is exchanged between the blood and air.

Slide 34: 

Muscles of the rib cage: Muscles attach to the ribs causing the rib cage & chest/thoracic cavity to expand or compress. Muscle of the diaphragm: Separates the thoracic cavity from the abdominal cavity

Laryngeal System : 

Laryngeal System Voice is produced by the vibration of two vocal folds within larynx Primary Fcn of larynx: guard away against aspiration. where: top of trachea swallow it elevates and contract to protect airway Aid in coughing, vomiting Lifting, defecation, childbirth (valsalva maneuvers)

Larynx : 

Larynx Larynx- (voice box) Bone, cartilage, & muscles Cartilages of the larynx: Thyroid Cartilage Cricoid Cartilage Arytenoid Cartilages These jointed, movable cartilages, along with their attached muscles, stretch and contract the vocal folds.

Slide 37: 

Thyroid cartilage butterfly-shaped cartilage, largest part of larynx Cricoid cartilage signet-ring shaped, narrow band on front, wider band on back, attaches to third tracheal ring (top of trachea) Arytenoid cartilages two pyramid shaped cartilages, sit on top of wide part of cricoid (vocal folds attached and move with help of arytenoids) rocking and gliding motion

Slide 38: 

Glottis Space between vocal folds Hyoid bone U-shaped bone from which larynx is suspended. Only bone in larynx. Articulates (point of attachment) with the thyroid cartilage Laryngeal Structures

Slide 39: 

Epiglottis- made of cartilage, keeps food or foreign material out of airway and larynx Remains upright during breathing Drops and inverts during swallowing to divert material (food, liquid, saliva) from the airway to the esophagus

Phonation : 

Phonation Muscles inside larynx can cause the folds move apart (abduct) or come together (adduct) Fast! Opening & closing = one cycle of phonation Bunch of cycles for phonation. Vibrations per second- Hertz

3 Cavities : 

3 Cavities Pharyngeal cavity or Pharynx: 3 areas: nasopharynx, oropharynx, laryngopharynx immediately above the larynx- called the pharynx study by videoendoscopy which is lens in the throat Shows the shape for speech sounds

Slide 42: 

Nasopharynx Oropharynx Laryngopharynx

Cavities : 

Cavities Oral Cavity Roof formed by hard palate at the anterior and soft palate/velum posteriorly (uvula) Nasal Cavity Top of hard and soft palate Most speech sounds the velum is raised to close off nasal cavity except nasal sounds /m/ and /n/ /ng/ Hypernasality-excessive nasal Denasality-insufficient nasal resonance

Slide 44: 

Alveolar Ridge- houses upper teeth Hard palate- bony structure behind alveolar ridge, divides nasal and oral cavity Soft palate- (VELUM) soft tissue attached to hard palate. Raises to block off or occlude the nasal cavity The major players: tongue, mandible, teeth, hard palate, and velum

Slide 45: 

Hard PalateSoft PalateTongueEpiglottis