Articulatory System: Physiology Flashcards
Source filter theory
- Sound source (V+ or V-) from larynx
- Filter (vocal tract modifies sound source)
2.5. Noise source (vocal tract can also be new “source” of noise)
- Speech sound (what we perceive as speech)
What is a filter?
Tubes= filter
Every “tube” or filter has a natural HZ that they highlight/emphasize/resonate with when a sound is passed through them
Other Hz, they downplay
How does vocal tract act as a filter?
When you introduce a complex glottal sound to one end of a vocal tract, the vocal tract filters the frequencies by highlighting resonant Hz.
Results in sound exiting other end of vocal tract as filtered version of complex sound. This filtered sound= recognized as speech!
These highlighted Hz are called formants (frequency peaks) that make speech sounds identifiable
Vocal tract constantly changes shape during speech, resulting in changes of natural resonant Hz constantly
Results in continually different filtered sounds (Speech)
Vocal tract is highly malleable tube that continually filters complex sounds into perceived speech
What is the vocal tract?
Flexible, durable, double-barreled tube that can rapidly change chape with 3 cavities
What ways can the 3 cavities be modified in?
- Pharyngeal cavity: Length and diameter
- Oral cavity: Shape and opening
- Nasal cavity: added or subtracted
Modifications leads to highlighting different pitches, noise source, or nasal quality respectively
Modifying pharyngeal cavity
Basics:
1. Assume voiced glottal source for ease
2. Assume nasal cavity subtracted for ease
3 ways to modify pharyngeal cavity:
1. Length
Lengthen or shorten
2. Diameter
Narrow or widen
3. Combination
Rule of thumb formants
Smaller cavity: highlights higher Hz
Larger cavity: highlights lower Hz
Lengthening pharyngeal cavity
Lowering the larynx via infrahyoid muscles
Results in larger cavity, highlighting lower Hz
Remember, when larynx goes down, lower Hz
Shortening pharyngeal cavity
Raising the larynx via suprahyoid muscles
Results in smaller cavity, highlighting higher Hz
Narrowing pharyngeal cavity
Constricting pharyngeal walls via the pharyngeal constrictors
Results in smaller cavity size, highlighting higher Hz
Widening pharyngeal cavity
Widening pharyngeal walls via relaxing the constrictors, or with stylopharyngeus
Results in larger cavity, highlighting lower Hz
Combination of length and diameter of pharyngeal cavity
Shorter and narrower: Highest Hz
Longer and wider: Lowest Hz
Theory of vowel production
Basics:
1. Assume voiced glottal source since all vowels are voiced
2. Assume nasal cavity subtracted since all vowels in English are not nasal
2 ways oral cavity is modified:
1. Shape of oral cavity via tongue and mandible position
2. Shape of exit via lip and mandible position
Oral cavity changes create the formants for vowels
Vocal tract reimagined
Rethink oral cavity as a curved open tube of air ignoring all muscles and bones can be change in shape in combination with pharyngeal cavity
Same as actual vocal tract
Modifying oral cavity for vowels
3 ways:
1. Vertical jaw/tongue placement
Height: high/low
2. Horizontal tongue placement
Front/back
3. Lip rounding
Rounded/unrounded
/i/
High, front tongue
unrounded
Muscles:
Vp closers: Levator palatini and Superior constrictor
Tongue: Geniohyoid, mylohyoid, digastric (anterior), Vertical (flatten),
Lips: Risorius
/u/
High and back tongue
rounded
Muscles:
Vp closers: Levator palatini, superior constrictor
Tongue: Palatoglossus, styloglossus
Lips: Orbicularis oris, incisivus labii superior/inferior
/a/
Low and back tongue
unrounded
Muscles:
Vp closers: Levator palatini, superior constrictor
Tongue: Hyoglossus, vertical (flatten)
Mandible: Mylohyoid, geniohyoid, digastric (anterior) (depressors)