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Focus: Relaxation Pressure Curve. Speech Science COMD 6305 William F. Katz, Ph.D. Univ. Texas Dallas. Lung Volumes and Vital Capacity. Note : Above VC:. Relaxation Pressures. R.E.L. Inspiration (Muscular). Expiration (P). Expiration (M). Inspiration (Passive). Inspiration.
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Focus:Relaxation Pressure Curve Speech Science COMD 6305 William F. Katz, Ph.D. Univ. Texas Dallas
Lung Volumes and Vital Capacity Note: Above VC:
Relaxation Pressures R.E.L Inspiration (Muscular) Expiration (P) Expiration (M) Inspiration (Passive) Inspiration Expiration Target: 8-10 cm H20 for speech
Relaxation Curve Shows the system is elastic in nature… B. Relaxation pressures are balanced C. Chest wall reaches its resting size D. Elastic recoil forces of both chest wall and lungs act to decrease overall volume • Little force on lungs to decrease (black arrows); big elastic recoil forces act on chest wall to expand it outward (gray arrows) Inspiration Expiration Cycle: Inspiration Expiration
Tutorial requires checking right pressure for speech requires forced abdominal effort http://www.screencast.com/t/NwYFlpctdP
Summary – Key points Most speech is at about 60% of VC Pressure: 8-10 cm H20 (On graph: close to equilibrium point of balanced elastic and recoil forces)
Key points – cont’d Expiration for speech is an active process: Inspiratory muscles used for “checking” (braking) action This is increasingly true for larger volumes of air intake