Phonation & Posture Flashcards
Define Elastic recoil
ability of a stretched object or organ to return to its resting position or equilibrium (state of balance: stable, neutral, instable)
Male & Female Vocal fold length
Female 12.5mm-17.5mm
Male 17mm-25mm
The Bernoulli Effect
Increased motion of gas molecules=decreased pressure
6 steps of Self-Sustained Vocal Fold Vibration
No Bernouli Effect required
- Vocal folds have a stable equilibrium when adducted
- Airflow, generated by lung pressure, moves folds apart (away from equilibrium)
- Elastic recoil kicks in (folds want to return to equilibrium)
- Momentum carries folds past equilibrium
- Folds want to, again, return to equilibrium (from the other direction)
- Airflow, generated by lung pressure, again moves vocal folds apart (away from equilibrium)
4 Factors that determine Fundamental Frequency (F0) and Intensity of Sound:
- Vocal fold tension or glottal resistance
- Aerodynamic power (ratio of Psub to air flow)
- Length of the vocal folds
- Mass of the vocal folds
How much airflow do singers use compared to non-singers?
Singers get 2-3X greater peak airflow for a given lung pressure than non-singers -they achieve optimum transfer between vibrator and resonator
What is Subglottic Pressure AKA “Psub”?
Pressure that builds up at the vocal fold level
Glottis
opening between the vocal folds
4 Indications of an improper amount of Subglottic pressure
- Decreased flexibility/stability
- Voice cracking/excess noise in the sound
- Breathy sound/lack of clarity in the sound (not enough)
- Outward signs of strain (perhaps this goes without saying)
How much Psub for each?
Very soft Phonation
Normal Speech
Loud sounds
Heavy lifting
Very soft Phonation-3cm H2O
Normal Speech 4-9 cm H2O
Loud sounds - 20-70 cm
Heavy lifting - 150 cm
Gauffin & Sundberg (1989) “Flow Phonation” is…
Highest possible air flow with complete [optimal-Dr. Gill] glottal closure
1mm increase in glottal width achieves…
Boost of 3dB for 1mm increase in glottal width due to increased air flow (possible to achieve up to 4-7dB increase with GW increase as opposed to 8-9dB with doubling Psub.)
dB increase from doubled Psub?
8-9dB increase with doubling Psub
3 Results of over-adducting the vocal folds?
- Causes Potential tissue damage and fatigues intrinsic and extrinsic musculature
- Suppresses natural modes of vibration, diminishing their effectiveness as an acoustic power source
- Cause constrictive tensions that can diminish the efficacy of good resonances
At low frequencies, what regulates pitch and intensity?
glottal resistance (degree and closure time)