Lip and vocal fold vibration is driven by Bernoulli pressure reduction from airflow
Evidence
The lips (or vocal folds) have to be brought close together before we can initiate vibration (in the case of the vocal folds, this action is known as vocal fold adduction, and the gap between the vocal folds is known as the glottis), and therefore the aperture at the mouth is narrowed by the closer approximating lips (the airway through the larynx is narrowed at the glottis by the adducted vocal folds, as illustrated in the right-hand part of Figure 4.25). Air flowing out from the lungs flows around the lips (or vocal folds) and thereby causes a reduction in pressure around the outer (upper) curved surfaces of the lips (vocal folds), which will provide a force away from the center of curvature that starts to move the lips (folds) both outward (upward) and toward each other. Once they start to move, the gap between the lips (the glottis in the case of the vocal folds) becomes narrower, causing the airflow to increase further, since the gap between the lips (or glottis for the vocal folds) is narrower. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1240
Categorization
- DEFINE: Defines vocal fold adduction and the glottis while explaining the Bernoulli mechanism that drives lip/fold oscillation.
- XREF: connects to: The vocal folds vibrate via pressure changes from curved airflow, not the Bernoulli effect — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1325; The Bernoulli effect is a wrong explanation for vocal fold vibration — Eric J. Heller, Why You Hear What You Hear- An…, 1661; Curved-surface airflow, not the Bernoulli effect, drives lip vibration. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1238 (+16 more)
Broader Connections
- The vocal folds vibrate via pressure changes from curved airflow, not the Bernoulli effect
#contradicts(0.95) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1325 - The Bernoulli effect is a wrong explanation for vocal fold vibration
#contradicts(0.93) — Eric J. Heller, Why You Hear What You Hear- An…, 1661 - Lip vibration self-sustains through Bernoulli pressure and elastic recoil
#corroborates(0.92) - Curved-surface airflow, not the Bernoulli effect, drives lip vibration.
#contradicts(0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1238 - Bernoulli’s airflow across curved lips initiates their vibration
#corroborates(0.90) - The Bernoulli effect couples airflow velocity to reduced pressure at constrictions
#expands(0.88) - Elastic recoil and momentum, not Bernoulli effect, mainly close the vocal folds
#complicates(0.85) - Lift on curved surfaces comes from a pressure gradient, not the Bernoulli effect
#exemplifies(0.85) - Pressure dynamics make vocal folds close faster than they open
#expands(0.82) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1326 - Vocal fold oscillation frequency is predictable without invoking aerodynamic forces
#complicates(0.78) — Eric J. Heller, Why You Hear What You Hear- An…, 1735 - Lip oscillation sustains continuously while airflow and adduction persist
#qualifies(0.76) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1242 - Elastic lips and vocal folds self-oscillate once energy input begins.
#qualifies(0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1237 - Speech production reduces to lungs as compressor driving a glottal oscillator through resonating tracts
#qualifies(0.74) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 598 - Whispering replaces vibrating vocal folds with jet turbulence as the sound source
#complicates(0.73) — Eric J. Heller, Why You Hear What You Hear- An…, 1343 - Voiced speech originates from airflow through the vibrating vocal folds across the glottis
#expands(0.72) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 548