CDO 463 7 Consonants

  1. Consonant Production
    Source-Filter Theory: 
    • Acoustic theory of speech production
    • –Speech is results from a combination of sound source(s) and the filtering provided by the vocal tract.
  2. Sound sources for consonants
    • –Periodic vibration:  voice
    • –Aperiodic vibration
    • •Turbulent:  sustained noise
    • •Transient:  single vibration (gunshot)
  3. Descriptive Phonetics
    • –Manner of Articulation:  how the consonant is produced
    • –Place of Articulation:  where the consonant is produced
    • –Voicing:  are the vocal folds vibrating
    • •Each descriptive phonetic phonemic feature has an acoustic realization
  4. Stop (plosives):
    • –Descriptive:  sound produced with a complete blockage (both oral and nasal cavities) of the vocal tract during which time no air flows and pressure increases.  An explosion occurs at the release.
    • –Acoustic:  period of silence (complete blockage of vocal tract) followed by a burst of energy (release of air pressure).  Burst is a transient vibration.
  5. Fricative:
    • –Descriptive:  sound produced with a partial oral cavity blockage (nasal cavity blocked).  Air pushed through the blockage becomes turbulent
    • –Acoustic:  sound produced with a period of sustained noise
  6. Affricate:
    • –Descriptive:  combination of a stop (complete blockage of both oral and nasal cavities) released to a fricative (partial blockage)
    • –Acoustic:  period of silence followed by a burst of energy followed by sustained noise
  7. Approximant:
    • –Descriptive:  sound produced with the least constricted vocal tract of all the consonants
    • –Acoustic:  formants like vowels.  Multiple formants, although usually weaker than the surrounding vowels
  8. Nasal:
    • –Descriptive:  sound produced with an oral cavity blockage but with the nasal cavity coupled to the vocal tract resulting in nasal resonance.
    • –Acoustic:  formants like vowels.  Low formant reflecting nasal resonance.  Higher formants usually weak or absent
  9. Acoustic Characteristics of Place of Articulation
    Varies depending on the manner of articulation
  10. Stop consonants: 
    –transition (movement-change in frequency over time) of the second and third formants
  11. Fricatives: 
    –frequency location and strength of the noise energy
  12. Approximants: 
    –onset (beginning) frequency of the second and third formants
  13. Nasals: 
    similar to the stop consonants
  14. Acoustic Characteristics of Voicing
    Voicing varies depending on the manner of articulation and position in word (initial/final)
  15. Stop consonants
    • •Initial (prevocalic) position:  Voice Onset Time (VOT):  time between the release of the stop and the onset of voicing for the following vowel
    • –Voiceless:  long time interval (> 50 msec)
    • –Voiced:  short time interval (<20 msec)
    • •Final (postvocalic) position:  Preceding Vowel Duration
    • –Voiceless:  vowel is shorter
    • –Voiced:  vowel is longer
  16. Fricatives
    • •Initial (prevocalic) position:
    • –Voiceless:  no voicing during the fricative
    • –Voiced:  voicing during the fricative
    • •Final (postvocalic) position:  same as the stop consonants
Card Set
CDO 463 7 Consonants
acoustic characteristics of consonants