Speech acoustics quiz 4 - production of speech sounds

What are the valves of the vocal tract?

Labial, lingual, velopharyngeal, and laryngeal

Labial valve consists of

lips

What is the labial valve resposible for?

the lips shape and restrict air flow

In the labial valve, what contacts each other?

lips contact each other and the teeth

Lingual refers to…

tongue

Lingual valve can contact

the teeth, alveolar ridge, and hard/soft palate

The lingual valve is responsible for?

external extension (lets us extend our tongue outside of our mouth) and changing the volume of the oral cavity (from small to large)

Velopharyngeal velum consists of

velum (soft palate), posterior & lateral pharyngeal wall

What is the velopharyngeal valve responsible for?

directing airflow to the oral or nasal cavity

The laryngeal valve consists of…

vocal folds

What is the laryngeal valve responsible for?

voicing

Where do speech sounds come from?

Features a source, a filter, and output

What is the source where speech sounds come from?

Vocal folds! They create a glottal wave which produces fundamental frequency and harmonics. Fundamental frequency depends upon the rate and tension of vocal fold vibration.

True or false: True vocal folds move the air through rarefaction and compression

True

What is the filter that speech sounds come from?

The vocal tract! It contains valves (tongue, lips, velum, pharynx) that change pharyngeal, oral, and lip volumes. These changes create resonances called formants.

The vocal tract is also known as the…

resonating tube

Formants are based on…

length and width of vocal tract

What is the output that speech sounds come from?

output at the lips which creates speech, the fundamental frequency and harmonics are unchanged but the amplitude changes

Periodic complex sounds

a series of frequencies that are related to each other

In periodic complex sounds, what are fundamental frequencies?

the lowest frequency of the sound

In periodic complex sounds, what are harmonic frequencies?

frequencies above the fundamental frequency (these are even multiples of the fundamental frequency)

Examples of periodic complex sounds

a musical instrument or producing speech

Examples of fundamental frequencies (F0) and harmonic frequencies (just look at briefly)

F0 (fundamental frequency) = 100 Hz. Harmonics = 200 Hz, 300 Hz, 400 Hz, etc.

F0 (fundamental frequency) = 300 Hz. Harmonics = 600 Hz, 900 Hz, 1200 Hz.

Aperiodic complex sounds

two or more frequencies, but they’re not related to each other.

In aperiodic complex sounds, what happens with the fundamental frequency?

These sounds will still have a fundamental frequency, but the later frequencies (harmonics) are all over the place and will not increase in even multiples like a periodic complex sound. The later frequencies will not be related to the fundamental frequency.

Examples of aperiodic complex sounds (just look at briefly)

contains all frequencies between 100Hz and 600Hz or contains all frequencies between 2000Hz and 5000Hz

Examples of aperiodic complex sounds

clapping hands

If we have the source of speech sounds, we need the resonator, which is…

the vocal tract that serves the vocal tract transfer function (which is how the vocal tract changes the sound coming from the vocal folds)

Two types of resonators

mechanical and acoustic

Mechanical resonator

an actual object is set into vibration

Acoustic resonator

a receptacle is filled with air

What resonator do we use for speech?

acoustic resonator

Mechanical resonator resonance details

Driving frequency - the frequency produced by the first object. Resonator - the second object that receives the sound and vibrates in response. The closer the driving frequency is to the resonator's frequency, it causes a larger amplitude.

Acoustic Resonators resonance details

Air can resonate in an enclosed space. Smaller volumes of air will resonate at higher frequences, larger volumes of air will resonate at lower frequencies.

Is the vocal tract a series of tubes or one long tube?

One long tube (known as the resonating tube)

Helmholtz Resonators

a space filled with air that can resonate

True or false: Valving of Vocal Tract results in a series of Helmholtz Resonators

true

Valving of Vocal Tract

The vocal tract contains air-filled cavities (pharynx, oral, and nasal). Vocal tract valves open and close these cavities. These cavities vibrate/resonate in response to sound waves from the vocal folds. Vocal tract resonances aren’t dependent on fundamental frequency, but instead of length and width of the cavities.

Anterior border of oral cavity

teeth/gums

Superior border of oral cavity

hard palate/soft palate

Floor of oral cavity

mylohyoid and geniohyoid

Posterior border of oral cavity

palatoglossal arch

Functions of the tongue

Swallowing and articulation

Oral tongue

anterior (front) 2/3rds of the tongue, within the oral cavity

The oral tongue includes the…

tip, blade, front, and back

Pharyngeal tongue

posterior (back) 1/3rd of the tongue (aka the tongue base).

Is the oral tongue or pharyngeal tongue within the oropharynx?

Pharyngeal tongue

What happens with a tongue tie?

The frenulum becomes short. The person will potentially have speech production and swallowing issues. Severity varies based on the length of the frenulum. Sometimes, there is no issue for them to produce speech sounds.

This is showing…

a short frenulum

This is showing…

a normal frenulum

This is showing…

double frenulum, very rare

Features of the oral tongue

Has thick, rough covering and features a midline depression called the longitudinal sulcus

Pharyngeal tongue features

smooth thin, nodular covering due to presence of tonsils in submucosa

The tongue assists with…

Fine motor movements, acts as a valve, and modifies airsteam

Anatomical parts of the tongue?

tip/apex, blade, front (under hard palate), back (under soft palate), dorsum (broad superior surface - runs from front to the back of the tongue)

Anatomical parts of the tongue shown flat

Anatomical parts of the tongue shown flat

What is b?

tip/apex

What is c?

blade

What is d?

dorsum (body)

What is e?

root

In this image, where would the front and back be?

Front of d and back of d

Are muscles of the tongue bilateral or unilateral?

bilateral, with 2 sides separated by the median septum

Median septum

a fibrous divide that runs from tongue tip to hyoid bone (doesn’t reach surface of tongue)

What is I pointing to?

median septum

Intrinsic muscles of the tongue (FUNCTION)

Shape the tongue and makes fine motor movements for speech

Extrinsic muscles of the tongue (FUNCTION)

Positions and shapes the tongue for speech and swallowing

What are the intrinsic muscles of the tongue?

Superior longitudinal, inferior longitudinal, transverse, vertical

Superior longitudinal muscle

Shortens tongue; turns tip upward; unilateral turning of tip

Inferior longitudinal muscle

shortens tongue; pulls tongue tip downward

Transverse muscle

narrows and elongates tongue

Vertical muscle

flattens and widens tongue

Extrinsic Muscles of the tongue

genioglossus, styloglossus, hyoglossus, palatoglossus

genioglossus muscle

protrudes tongue, and depresses central portion

styloglossus muscle

lifts sides of tongue, pulls tongue backward

hyoglossus muscle

pulls down sides of tongue, pulls tongue backward (retracts)

palatoglossus muscle

elevates and retracts tongue base

What is CN XII (12th cranial nerve)?

hypoglossal nerve

Where does the hypoglossal nerve start?

In the motor cortex of the brain

Hypoglossal nerve

Information from the motor cortex is projected bilaterally to the hypoglossal nuclei/nerve to control most tongue muscles, except for one.

What is the exception to the hypoglossal nerve?

The genioglossus muscle. Neurons that drive this muscle project only to the contralateral hypoglossal nuclei/nerve

Therefore, to test integrity of the hypoglossal nerve (CN XII), what would you do?

Test the action of the genioglossus. An example would be sticking your tongue out. Any damage to this area will result in the patient sticking their tongue out to the side rather than straight out

The tongue can be described as a muscular hydrostat, which means…

It is like a fluid filled, incompressible bag. The muscles serve as the fluid.

The tongue is a “constant volume” system, meaning…

any reduction in volume in one part of the tongue will result in an equal increase in volume in another part of the tongue

What muscle is used for protrusion (sticking the tongue out)?

Genioglossus

What muscle is used for retraction (pulling the tongue back)?

Styloglossus (major), hyoglossus (minor)

What muscle(s) is used for lateralization (moving the tongue back and forth)?

genioglossus, styloglossus, hyoglossus