Physiology of Speech ProductionDr Sisha Liz : Physiology of Speech ProductionDr Sisha Liz Pictures from body works Systems : Systems Respiratory 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
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
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
size and mass effects
Pitchthe 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 intensityaerodynamic 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:
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
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
Brain and spinal cord
Other nerves connect to brain and spinal cord CNS : CNS Brain
Higher level function
Separated by Corpus Callosum Four Lobes : Four Lobes Brain
Try and label them! Frontal : Frontal Functions
Primary motor cortex
Plan speech and movements with cerebellum Parietal : Parietal Primary sensory cortex
Pain Occipital : Occipital Receive and process visual info Temporal : Temporal Process hearing
Primary auditory cortex
Hear speech and process it Parts for S & L : Parts for S & L Most people process language in the left hemisphere
Left frontal lobe
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:
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
signet-ring shaped, narrow band on front, wider band on back, attaches to third tracheal ring (top of trachea)
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
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)
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)
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/
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