Phonation CSD353

What are the vocal folds?

Valves that open and close to perform various functions.

From superior to inferior: Ventricular Fold,

Laryngeal Ventricle,

Vocal Fold.

Describe the composition of the VF

Five layers; Single Epithelial, Triple Mucus Membrane, Double Muscle.

How many layers of the true vocal folds?

Five

Outermost layer of the true vocal folds

Squamous Epithelium

Second Layer of the true vocal folds (Made up of _____ parts)

Lamina Propria - Mucus Membrane;

1. Superficial lamina propria (Loose fibers),

2. Intermediate Lamina Propria (Dense fibers),

3. Deep Lamina Propria (Densest fibers)

Third Layer of the true vocal folds (Made up of ___ parts)

Thyroarytenoid Muscle;

1. Thyrovocalis Part (Superficial)

2. Thyromuscularis Part (Deep)

Definition: Medial Edge

Definition: Cover

The outer two layers of the true vocal folds. Epithelium and Superficial Lamina Propria

Slides include the Transition with the cover.

Definition: "vocal ligament"

The "transition" The 3rd and 4th two layers of the true vocal folds. Intermediate Lamina Propria and Deep Lamina Propria.

Definition: Body

The thyroarytenoid muscle forms the body of the vocal cords.

What is the stiffest layer of in the cover-body model?

The body. Goes from less to more stiff from superficial to deep.

How do the terms "medial edge" "cover" and "body" relate to the VF?

Neurochronaxic Theory of Phonation

1. Neuromotor impulse to vocals that abducted (<-->) the cords.

2. Adduction (>---<) via relaxation.

Believed there was 1 neuromotor impulse per cycle.

Myoelastic Aerodynamic Theory

This model of phonation describes voice production as an interaction between muscle force, tissue elasticity, and air pressures and flows.

Definition: "Myo"

Related to muscle; "Interaction of muscle force"

Definition: "Elastic"

Tissue Elasticity

Definition: "Aerodynamic"

Air Pressures and Flows

How do the terms "myo", "elastic", and "aerodynamic" relate to VF vibration?

When the glottis is closed by medial compression, the Subglottal Pressure increases.

When the vocal cords are forced apart by the pressure overcoming the muscle, a puff of air escapes setting the air in the tract into vibration and creating a sound wave.

Sound wave transmitted through the vocal tract where it's articulated and resonated.

They recoil back to the midline due to the natural elasticity which causes a negative pressure due to Bernoulli's Principle. The negative pressure between the folds closes them by pulling them closer together.

How does the term "periodic" relate to the VF?

The way that the vocal folds are made up and work means that they do not vibrate in a completely periodic manner.

Description of a "typical voice" using objective measures.

Description of an "atypical voice" using objective measures.

Breathy Voice: Vocal folds do not come together completely, and continuous air comes out through entire cycle. Air adds frication noise. Breathiness noticeable in higher frequencies (2k+)

Rough/Hoarse Voice: Very common symptom indicating vocal problem. Roughness is related to how periodically the vocal folds are vibrating. Rough/Hoarseness noticeable at lower frequencies (~1k)

Describe perceptual measures of phonation.

Male Speaker

Female Speaker

Child Speaker

Adult Speaker

Conditions that influence the fundamental frequency...

Speaking fundamental frequency

Why are semitones measured?

How is Hz related to semitones?

What intensity constitutes a "quiet voice?"

What intensity constitutes a "loud voice?"

What intensity constitutes a "typical vocal loudness?"

How do you know if someone is using "monotone" prosody?

Define: "Perturbation"

Define: "Variability"

Describe: "Voice Range Profile"

Voice Range Profile of a healthy voice

Voice Range Profile of an atypical voice

Define: "Noise"

Define: "Signal"

Explain: "Vocal Registers"

Define: "Phonation Threshold Pressure"

How is PTP related to vocal register?

How is an electroglottograph (EGG) signal (Lx Waveform) obtained?

EGG

Electroglottograph

Name of EGG Signal

Lx Waveform

Characteristics of Lx waveform for _____ voice

Purpose of viewing the vocal cords?

Define: "Stroboscope"

Define: "Steady Light"

Define: "Locked"

Define: "Traveling Wave"

Define: "Videostroboscopy"

Define: "Endoscopy"