Wednesday, November 6, 2013

LJ - Chapter 1 - Articulation and Acoustics



"Phonetics is concerned with describing speech."


 How are speech sounds made?
  • Audible tongue and lip gestures that involve pushing air out of the lungs while producing noise in the throat or mouth.
  • Producing any sound requires energy.
    • The basic source of power is the respiratory system. 
What are articulators?
  • Parts of the vocal tract that can be used to form sounds.
  1.  Tongue
  2.  Lips
Where does air travel?
  1. Respiratory system pushes air out of lungs.
  2. Trachea
  3. Larynx
  4. Vocal folds
  5. Pharynx
  6. Mouth
 What happens in the vocal folds?
  • Voiced sound: The vocal folds are adjusted so that there is only a narrow passage between them, the airstream from the lungs cause them to vibrate. (i.e., [v])
  • Voiceless sound: The vocal folds are apart. (i.e., [f])
What is the vocal tract? 
  • The air passage above the larynx.
  • Its shape is an important factor in speech production.
  • Drawing
    • Air passages that make up the vocal tract may be divided into the oral tract, within the mouth and pharynx, and the nasal tract, within the nose.
  • Air goes in and out through the nose when the flap at the back of the mouth is lowered.
What are the 4 main components of speech production mechanisms?
  1. Airstream process
  2. Phonation process  
    • The name given to the actions of the vocal folds. 
    • The two possible sounds produces are voiced and voiceless.
  3. Oro-nasal process
    • Airstream going out through the nose.
  4. Articulatory process
    • The movements of the tongue and lips interacting with the roof of the mouth and the pharynx.

How do we hear sounds?
  • Depends on acoustic structure.
How do we describe speech sounds?
  1. Pitch
  2. Loudness
  3. Quality
 What are the common characteristics of sound waves?
  • Voiced sound: Vibrating vocal folds have comparatively large regular pulses of air pressure.
  • Voiceless sound: Sounds without vocal fold vibration have a smaller amplitude and irregular variations in air pressure.

What do articulators do?
  • Lower surface of the vocal tract make the gestures required for speech by moving toward the articulators that form the upper surface.
 What are the principal parts of the upper surface of the vocal tract?
  1. Alveolar ridge
    • Small protuberance just behind the upper teeth.
  2. Hard palate
    • Bony structure in the front part of the roof of the mouth.
  3. Soft palate (Velum)
    • A muscular flap that can be raised to press against the back wall of the pharynx and shut off the nasal tract. 
  4. Uvula
    • A small appendage hanging down at the lower end of the soft palate.
  5. Pharynx
    • The part of the vocal tract between the uvula and the larynx.
    • The back wall of the pharynx may be considered as one of the articulators on the upper surface of the vocal tract.
  6. Larynx

What is a velic closure?
  • It's when the velum is press against the back wall of the pharynx and shuts off the nasal tract, preventing air from going out through the nose.
  • This action separates the nasal tract from the oral tract so that the air can only go out through the mouth.
What are the principal parts of the lower surface of the vocal tract?
  1. Lower lip
  2. Tip of the tongue
  3. Blade
  4. Front of the tongue: Located behind the blade, It is the forward part of the body of the tongue that lies underneath the hard palate when the tongue is at rest.
  5. Center of the tongue: Partly beneath the hard palate and velum.
  6. Back of the tongue: Beneath the soft palate.
  7. Root of the tongue: Opposite the back wall of the pharynx.
  8. Epiglottis: Attached to the lower part of the root of the tongue.
What are the most mobile parts of the tongue?
  1. Tip of the tongue
  2. Blade of the tongue
How are the speech articulators categorized?
  1. Labial: Uses the lips.
  2. Coronal: Uses the tip/blade of the tongue.
  3. Dorsal: Uses the back of the tongue.
What are the principal terms for the particular types of obstruction required in the description of English?

  1. Bilabial: Upper and lower lip.
    • (i.e., pie, buy, my)
  2. Labiodental: Lower lip and upper front teeth.
    • (i.e., fie, vie)
  1. Dental: Tongue tip and upper front teeth.
    • (i.e.,thing, there)
    • Interdental: Tip of the tongue protruding between the upper and lower front teeth.
  2. Alveolar: Tongue tip or blade and the alveolar ridge.
    • (i.e., tie, die, nigh, sigh, zeal, lie)
  3. Retroflex: Tongue tip and the back of the alveolar ridge.
    • (i.e., rye, row, ray, ire, hour, air)
  4. Palato-Alveolar: Tongue blade and the back of the alveolar ridge.
    • (i.e., shy, she, show)
    • Post-alveolar: Blade of the tongue is close to the back part of the alveolar ridge and sounds are produced farther back in the mouth.
  5. Palatal: Front of the tongue and hard palate.
    • (i.e., you)
  1. Velar: Back of the tongue and velum.
    • (i.e., hack, hag, hang)
    • (i.e., Velar: rang, Alveolar: ran, Bilabial: ram)
    • Air comes out through the nose because air is prevented from going out through the mouth because the velum is lowered.

    What can articulators do?
    • Close off the oral tract for an instant or relatively long period.
    • Narrow the space considerably.
    • Modify the shape of the tract by approaching each other.
    6. STOP
    • Term commonly used to imply a complete stoppage of the airflow through both the nose and the mouth. 
    • Complete closure of the articulators involved so that the airstream cannot escape through the mouth.
    • Velic opening differentiates the types of stops.
    What are the possible types of stops?
    1. Oral stop
    2. Nasal stop
    6.1 ORAL STOP
    • Known as plosives in the IPA chart.
    • Pressure builds up inside the mouth when the mouth is closed and the velum is raised so that the nasal tract is blocked off, and the airstream is thus completely obstructed. 
    • The airstream releases a small burst of sound when the articulators come apart. 
    • (i.e. Bilabial closure: pie, buy, Alveolar closure: tie, dye, Velar closure: kye, guy)
    6.2 NASAL STOP
    • Air is stopped in the oral cavity but the velum is lowered so the air can go out through the nose.
    • (i.e., Bilabial closure: my, Alveolar closure: nigh, Velar closure: sang)
    • Close approximation of two articulators so that the airstream is partially obstructed and turbulent airflow is produced.
    • There is a narrowing of the vocal tract between the blade of the tongue and the back part of the alveolar ridge.
    • (i.e., Labiodental: fie, vie, Dental: thigh, thy, Alveolar: sign, zoo, Palato-alveolar: shy)
    What are sibilants?
    • Higher-pitched sounds with a more obvious hiss.
    • (i.e., sigh, shy)
    • A gesture in which one articulator is close to another, but without the vocal tract being narrowed to such an extent that a turbulent airstream is produced.
    • (i.e., yacht, we, raw)
    • Obstruction of the airstream at a point along the center of the oral tract, with incomplete closure between one or both sides of the tongue and the roof of the mouth.
    • No stoppage of air.
    • No fricative noises.
    • (i.e., Alveolar laterals: lie, laugh)
    • Sucking test: The tongue will feel colder on the side that is not in contact with the roof of the mouth.
    1. Trill (Roll)
    2. Tap (flap)
      • Tongue makes a single tap against the alveolar ridge.
    3. Affricate
      • Some type of articulation combined with a fricative.
    4. Glottal stop
      • In English, words that start with a vowel.
    What are the five factors used to describe consonants?
    1. State of the vocal folds (voiced or voiceless)
    2. Place of articulation
    3. Central or lateral articulation
    4. Soft palate raised to form a velic closure (oral sounds) or lowered (nasal sounds)
    5. Manner of articulatory action
    • Amplitude gets larger for vowels.
    • Articulators don't come very close together, and the passage of the airstream is relatively unobstructed.
    Vowel classification
    1. Front
    2. Back
    Lip movement
    1. Rounded
    2. Unrounded 
    • There is (voice) pitch at which the vowel is actually spoken. This depends on the pulses being produced by the vibrating vocal folds.
    • There are overtone pitches (vocal tract pitches) that depend on the shape of the resonating cavities of the vocal tract.
      • Gives the vowel its distinctive quality.
    • We normally cannot hear the separate overtones of a vowel as distinguishable pitches.
      • The only sensation of pitch is the note on which the vowel is said. This depends on the rate of vibration of the vocal folds.
      • But we hear it when we whisper.
    • Summary: Vowel sounds may be said on a variety of notes (voice pitches), but they are distinguished from one another by two characteristic vocal tract pitches associates with their overtones.
    What is a formant?
    1. F1: Lower pitch that is distinguishable in creaky voice.
    2. F2: Higher pitch that is heard when whispering.
    • Vowels and consonants can be thought of as segments of which speech is composed and they form syllables to make up utterances. 
    • Characterized by the fact that they must be described in relation to other items in the same utterance.
      • It is the relative values of pitch, length, or degree of stress of an item that are significant. But the absolute values are never linguistically important.
    What are the features of suprasegmentals?
    1. Stress
      • In English, stress distinguishes nouns from verbs.
    2. Pitch
      • An auditory property that enables a listener to place it on a scale going from low to high, without considering its acoustic properties.
      • ↑ Frequency = ↑ Pitch
      • Equated with a sounds' fundamental frequency.
      • Pitch changes due to variations in laryngeal activity can occur independently of stress change.
      • Associated with the rate of vibration in the vocal folds.
      • Voice pitch is altered to produce different notes measurable by frequency.
    What is frequency?
    • A technical term for an acoustic property of sound.
    • The number of complete repetitions (cycles) of a pattern of air pressure variation occurring in a second. 
    • Unit: Hertz (Hz)
    What is intonation?
    • The pitch pattern in a sentence.

    No comments:

    Post a Comment