Larynx

Voice Box

  • The larynx is suspended in the neck by the muscle groups

  • 1.5-2 inches in length and width

  • Testosterone influenced voices have larger larynx which give it the deeper range

  • Its movable

  • Made of several cartlidge and only one bone

    • All connected to one another by ligaments, membranes and muscles

  • As people get older cartilage solidifies which is why voices continue to change

  • It protects us

    • The vocal folds close to prevent food from entering the lungs

    • The cause us to cough when something tries to enter

    • The folds close tightly while swallowing

    • Food has to pass over the larynx to get to the esophagus

Framework of the Larynx

  • Hyoid Bone

  • Thyroid cartilage

  • Cricoid cartilage

Laryngeal Cartilages

  • Cricoid - the ring

    • Larger in back

    • sits atop the trachea

  • Thyroid - The shield

    • Adams apple

    • 2 fused plates forming a V in the front open in the back

    • Lower horns extend down the back over the sides of the cricoid

  • Arytenoids - the pyramids

    • Located on the superior, posterior part of the cricoid

    • They glide and rotate, moving our vocal folds

  • Epiglottis - the lead

    • closes over the larynx when we swallow

Muscular actions

Vocal Fold Adduction and Abduction

  • Posterior Cricoarytenoids: Swing the arytenoid cartilages apart, allowing us to breath (Abduction)

  • Lateral cricoarytenoids: swing the arytenoid cartilages close to one another cause the vocal folds to meet but not completely (Adduction)

  • Interarytenoids: complete the vocal fold closure (Adductors)

Pitch

  • Thyroarytenoids: shorten and increase the bulk of the vocal folds, lowering the pitch

  • Cricoithyroids: tilt the thyroid cartilage, causing the vocal folds to stretch and resulting in a higher pitcher

Vocal Fold Layers

Layers

  • Stratified Squamous Epithelium: Protection against foreign bodies, bathed in mucus

  • Reinke’s space: Watery, amorphous layer, gel like

  • Vocal Ligament - passes through the intermediate layer of the lamina propria

  • Thyroidarytenoid (vocalis) muscle (lateral to the vocal ligament)

Ventricular (False) Vocal folds

  • Set above the vocal folds

  • can adduct and is use in come scream style of singing

Vocal Folds Average sizes:

  • Soprano 14.9 mm

  • Contraltos: 16.6 mm

  • Tenors: 18.4 m

  • Basses 20.9 mm

Producing Tone

Phonation: vocal-fold vibration

Myoelastic-areodynamic Theory

  • myo - muscle

  • elastic - stretch

  • aero - air

  • dynamic - constantly changing

Vocal folds vibrate because

  • Muscles

  • Elasticity

  • Air pressure

    • Bernoulli Effect: The air pressure will drop when going through the narrow passage of a tube creating suction between the sides of the tubes

    • The air pressure creates puffs of air

Pitch

  • Number of vibratory cycles within one second = frequency

  • Singing A4 = folds have opened and closed 440 time/seconds

  • Muscles alter the thickness/longitudinal tension of the dols

Volume

  • louder = higher subglottal pressure, larger amplitude of vibration (distance from the midline)

Onsets

Balanced (simultaneous)

  • Coordinated approximation of focal folds

  • Onset vocal fold vibration happens in sync with onset of airflow

  • Adductor muscle activate just before phonation

  • Gentle medial compression

  • Like pulling a tissue out of a box

Breathy

  • Initiation of air flow prior to full adduction of vocal folds

  • Used in jazz and pop vocal styles

Glottal

  • Vocal folds adducted before onset of phonation and blown apart more violently than in a balanced onset

  • Hard glottal stops are hard on the voice because of extended medial compression

  • Used in MT, pop, jazz, R&B and when singing in German

Fry

  • A point of contention in the voice community

  • Includes growl

Release of Sound

  • Immediate Inhalation - most natural method of release

    • Tell the choir what you want

  • Less desirable release (can distort pitch, strain larynx / folds:

    • Closure of glottis: there is still pressure under the vocal folds

    • Closing the mouth: changes the vowel shape

    • Breathy: can disengage the breath