Session 9

• basic components of acoustic theory of speech production


  sound source + resonance cavity = acoustic ouput
• frication


  - noise when 2 articulators get close

  - air goes through a small opening where air molecules bounce off each other

  - sustained noise
• explosion


  articulatory closure followed by a quick release
• eddy flow


  - air molecules go through a small opening and bounce against each other; become non-linear

  - do not go straight through; creates the sound of /s/ or a voiced fricative like /z/

  - ex: three people try entering a door at the same time
• voiced fricative airflow


  has air flow from both eddy flow and vocal fold vibration
• consonant sounds with 3 sources


  voiced affricates ex: 'dz' in judge:

  (voicing, frication, and explosion)
• what sounds are produced with eddy flow?


  fricatives
• consonant sounds with one source


  - nasals (voiced): m, n, ng

  - semivowels (voicing): glides w, j, and liquids r and l

  - voiceless fricatives (noise): s,f, th, sh, h

  - voiceless stops (explosion): p, t, k
• consonants with two sound sources


  - voiced fricatives (voiced and noise): z, v, voiced th, voiced sh

  - voiced stops (voicing and explosion): b, d, g

  - voiceless affricate (explosion and noise): ch as in church
• in english phonemes, what are most phonemes produced with?


  one sound source
• are vowels more intense than consonants?


  yes, they are more open, sound source has VF vibration so there's stronger energy; continuant sound vs a stop
• does the velopharyngeal port have to be closed in order to have an oral sound?


  no, it can still be open a little bit, critical point of about 1 millimeter
• sonorants (similar to vowels)


  - nasals, liquids, glides

  - free airflow; articulation shapes vocal tract cavities

  - characterized mainly by formant freq.

  - have a periodic laryngeal source (all voiced)
• obstruents


  - stops, fricatives, affricates

  - restricted airflow

  - aperiodic sound sources in upper vocal tract

  - may be voiced or voiceless

  - voiced obstruents combine periodic and aperiodic sources
• voiced consonants


  includes all sonorants, periodic laryngeal source
• voiceless consonants


  supraglottal noise sources, aperiodic laryngeal source: h noise, aspiration
• stop bursts


  - release built-up pressure; transient noise
• potential question: defend whether or not you think the VF are articulators


  - they can be considered articulators because they interfere with airflow
• glides /j/


  - production similar to /i/

  - high front tongue position

  - genioglossus active

  - formant values are similar to /i/: low F1 and high F2

  - formant transitions vary depending on adjacent vowels
• glides /w/


  - production similar to /u/

  -high back tongue position and rounded lips

  - styloglossus, orbicularis oris active

  - formant values are similar to /u/: low F1 and low F2.
• liquids l & r


  - tongue tip raised toward alveolar ridge

  - l: tongue tip contact with alveolar ridge

  - r: no tongue tip contact; often retroflexed (tip bent back) and lip rounding

  - F3 low for r

  - F3 level for l
• oral sounds & the velum


  - most speech sounds are oral (non-nasal)

  - soft palate elevated

  - velopharyngeal port closed

  - levator palatini muscle active
• degree of VP closure


  - varies with phonetic context

  - tighter for oral obstruents (require airtight seal)

  - moderate for high vowels

  - looser for low vowels
• is the VP relaxed during oral sounds?


  yes
• does the soft palate/uvula have to go all the way back in the pharyngeal wall?


  no, it just has to be close enough for oral sounds
• nasal sounds & the velum


  - nasals require open VP port (lowered velum)

  - levator palatini muscle relaxed

  - palatoglossus muscle may actively lower velum

  - nasal cavities form a resonant chamber

  - not as intense b/c energy is absorbed in mucus, water, nose hairs
• where is the oral cavity blocked for nasal stops?


  - at the lips: m

  - at the alveolar ridge: n

  - at the soft palate: ng
• where does air flow typically move?


  - because the soft palate is down, air flow always goes to the path of least resistance (nasal cavity)

  - some air goes forward, but majority goes through path of least resistance
• anti-resonant


  - air hits the closure (lips, alveolar ridge, or palate) & air starts to bounce back towards glottis/VF

  - when anti-resonant hits formant they cancel each other out
• why do nasals have lower intensity energy?


  - they have anti-resonant with air flow that bounces back and cancels energy going forward

  - nasal cavity also dampens the energy making it less intense
• why do nasals have lower frequencies?


  - they have a longer tube of the sound to the nasal cavity

  - air will also be absorbed by mucus or nose hairs, causing the sound to be quieter
• opening the VP port creates...


  - a large resonant cavity

  - results in low-frequency nasal resonance
• production of fricatives


  - aperiodic sound source in upper vocal tract

  - airflow forces through constriction creates turbulence
• where can fricatives be formed in the vocal tract?


  - labiodental (f, v)

  - linguadental (voiced and voicless th)

  - alveolar (s, z)

  - postalveolar (sh)
• alveolar fricatives


  - tongue forms constriction at alveolar ridge

  - air flows through midline groove of tongue against teeth

  - short anterior cavity emphasizes higher frequencies
• postalveolar fricatives


  - tongue forms groove in alveopalatal region

  - lips are often rounded

  - longer anterior cavity emphasizes lower frequencies
• glottal fricative


  - h

  - no supraglottal constriction

  - usually involves turbulent noise at the glottis

  - vocal tract shape depends on following vowel
• production of stops


  - complete articulatory closure in oral cavity

  - VP port closed

  - oral release yields a transient noise source, also called a release-burst

  - cannot be prolonged
• stop place of articulation


  - bilabials: low frequencies

  - alveolar stops: higher frequencies

  - velar stops: burst frequencies (depend on following vowel)
• does a K or T have more air volume in the front of the tongue?


  - K would have a lower frequency

  - frequency depends on the amount of energy at the explosion of the sound