LING 314 WEEK 11

ultrasound

uses high frequency sound waves to visualize internal structures

- phonetics: tracks tongue surface (midsagittal or coronal planes during speech

- noninvasive, high temporal resolution & safe for repeated use

sound frequency spectrum

- infrasound: <20Hz

- audible sound: 20-20,000 Hz

- ultrasound: 20kHz - 100Mhz

- hypersound: above ultrasound

generation of sound waves

handheld probes/transducers generate high-frequency sound waves

piezoelectric crystals

materials that can convert mechanical energy into electrical energy and vice versa

Piezoelectric effect

the property of materials that can convert mechanical energy into electrical energy and vice versa

sound wave interactions with soft tissues and fluid-filled organs

allows most sound waves to pass through

sound wave interactions with denser structures

sound waves are reflected back to the transducer

interaction of sound waves at the boundary of two mediums

• ex. soft tissue vs. air

reflection: much of the transmitted wave bounces back

• occurs because wave cannot easily transfer its energy across the impedance boundary

reception of echoes

transducer that emits sound waves also receives echoes of waves as they bounce back

• time that it takes for echoes to return to transducer and strength (amplitude) of echoes can tell us about distance and characteristics of tissues encountered

image creation

ultra sound machine processes echoes by transducer to generate images

• base don distance and strength of reflected waves

• machine constructs a real time imae or video of internal structures

what can ultrasound examine for speech

• tongue shapes/fronting/retraction in vowels

• tongue root advancement/retraction in vowels

• tongue shape in bunched vs. retroflexed [r]’s

you want to see if younger people have a more protruded tongue in [θ] than older people. would ultrasound be an appropriate method for this study?

no

intrinsic tongue muscles

• superior longitudinal

• inferior longitudinal

• transverse/transversus

• vertical/verticalis

superior longitdudinal muscle

shortens tongue along surface which causes upward curl

• location: lies beneath mucuous membrane on upper surface of tongue

  • runs along length of tongue

  • muscle fibers that run longitudinally from root to apex of tongue

inferior longitudinal muscle

contraction shortens length of muscle along underside of tongue which causes downward curl

• located along underside of tongue

• runs along either side of genioglossus, medial to hyoglossus

• muscle extends from root towards apex

• runs parallel to SL

transversus/transverse muscle

narrows the tongue from side-to-side

• can elongate and vertically thicken the tongue

• helps in protrusion

• runs laterally across tongue

• originates at lingual septum and inserts into lingual margin

verticalis/vertical muscle

pulls upper surface of tongue downward

• contraction of vertical muscles flattens and widens tongue

• action is OPPOSITE to transverse

• runs perpendicular to transverse muscle

• more concentrated in anterior part of tongue

• wide at bottom than top

Scenario 1: The "cylindrical" narrowing:

Slowly transition from a wide, neutral mouth position to a very tense [u] vowel (as in “boot”), or try to narrow your tongue so it fits between your premolars without touching them. Focus on how the tongue seems to "thin out" sideways and stretch forward toward your lips.

Observation: The tongue becomes narrow and elongated.

primary muscle: transversus

The "retroflex" scoop:

Produce a retroflex [t] (as in Hindi/Bangla). Notice how the lateral edges and the tip of your tongue arch upward toward the hard palate, creating a "bowl" or "concave" shape along the superior surface.

Observation: The tongue length shortens along the top, pulling the tip and edges upward

primary muscle: superior longitudinal

The "lateral" bracing:

Say the sequence [ti-ti-ti-ti] several times while focusing on you are doing with the sides of the tongue dorsum/back. Do you feel like the tongue sides are bracing against your

molar teeth?

Observation: The tongue becomes flatter and wider, increasing its horizontal surface area

primary muscle: verticalis

The "sub-tongue" curl

Action: Imagine you are trying to lick a crumb off your bottom lip, or produce a very rapid alveolar flap as for the [t] part in “party”. Focus on the quick downward snap/pressure of the tongue tip toward the floor of the mouth.

Observation: The underside of the tongue shortens, pulling the tip downward and away from the roof of the mouth.

primary muscle: inferior longitudinal

true or false:

the lateral sound [l] in the word “middle” requires a narrow tongue, which involves activiate of both the transversus and inferior longitudinal muslces

false

a researcher is using an ultrasound setup to image the tongue along the coronal plane. given he acoustic properties of ultrasound and the physical shape of tongue during speech, which of the following phonetic features would be the most difficult to accurately quantify using this specific orientation.

a. distance between tongue root and posterior pharyngeal wall

b. difference in tongue height between a high and low central vowel

c. depth of central groove along tongue body during production of sibilant

d. lateral symmetry of tongue (whether left and right are at the same height)

a

true or false:

the transversus muscle fibers run laterally across the tongue and originate at the lingual margin and inserts into the lingual septum.

false

true or false:

within the tongue, inferior longitudinal muscle is positioned more medially than the styloglossus muscle

true