Theories of VibrationMyoelastic‐Aerodynamic theory doesn’t fully account for the ability to keep vocal folds vibratingrequires continual transfer of energy from airstream to tissuecyclic transfer of energyhow does that happen?Theories of oscillation, vibrationInteraction between biomechanics aerodynamicsWe provide pressurized air stream but how do we convert this airstream energy to the tissues?Biomechanics—Springelastictension in the systemFk = xK, wherex = displacementK = spring constantrepresents tensionBiomechanics--Dashpotviscous damper that opposes motion (not position)viscosity: resisting velocity (motion)FB = x’B, wherex’ = velocityB = damping constantin larynx, used to decrease velocity of mass (vocal fold) due to elasticity (spring)Biomechanics—MassinertialFM = x’’M, wherex’ = accelerationintertia accelerates the motionMechanical Oscillationare three criteria for mechanical oscillation ...stable equilibrium positioninertia in system to overshoot equilibriumnet energy loss in system = 0 (if oscillation is to be self‐ sustaining)consider mass vibrating on a springrestoring force due to elongation orcompression of springassociated inertia causes overshoot and oscillation occursbut, dies out soonneed ‘squirts’ of energy at periodic intervals to maintain oscillationCSD 3112 1st Edition Lecture 21 Outline of Last Lecture I. Phonatory Systema. PhonationII. Source Theoriesa. Galen b. Dodartc. Ferreind. HelmholtsIII. Movement Theoriesa. Neurochronaxicb. MyoelasticIV. Bernouli EffectV. Glottal Vibration CycleOutline of Current Lecture VI. Theories of VibrationVII. Biomechanicsa. Springb. Dashpotc. MassVIII. Mechanical OscillationCurrent Lecture Theories of Vibration- Theories of Vibrationo Myoelastic‐Aerodynamic theory doesn’t fully account for the ability to keep vocal folds vibratingo requires continual transfer of energy from airstream to tissueo cyclic transfer of energy how does that happen?o Theories of oscillation, vibrationo Interaction between biomechanics aerodynamics We provide pressurized air stream but how do we convert this airstream energy to the tissues?These 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.- Biomechanics—Spring o elastic tension in the systemo Fk = xK, where x = displacement K = spring constanto represents tension- - Biomechanics--Dashpoto viscous damper that opposes motion (not position) viscosity: resisting velocity (motion)o FB = x’B, where x’ = velocity B = damping constanto in larynx, used to decrease velocity of mass (vocal fold) due to elasticity (spring)- - Biomechanics—Mass o inertialo FM = x’’M, where x’ = acceleration o intertia accelerates the motion- Mechanical Oscillationo are three criteria for mechanical oscillation ...- stable equilibrium position- inertia in system to overshoot equilibrium- net energy loss in system = 0 (if oscillation is to be self‐ sustaining)o consider mass vibrating on a springo restoring force due to elongation oro compression of springo associated inertia causes overshoot and oscillation occurs but, dies out soono need ‘squirts’ of energy at periodic intervals to maintain
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