Lecture 1 - Perceiving the sounds of language

• DeCasper and Fifer (1980)


  Preference for mother's voice over unknown female.
• Mampe et al (2009)


  Newborn's cries reflect native language prosody
• Sounds are filtered, low frequencies are heard


  Babies can't tell difference between 2 non-native languages below 1000Hz
• Prosody


  • Pitch, loudness, timing
• Babies had lower heart rate


  When listening to target non-native story
• DeCasper et al (1999)


  Preserved prosody in utero
• Mehler et al (1988)

  
  

  Discrimination of native vs non-native language sounds

  French babies can discriminate french from russian
• Phonemes


  Classes of speech sounds in language
• Vowels


  Voiced, generate pitch and intensity
• Syllables


  Unit of speech, must contain a vowel
• Voice onset time


  Time between opening of lips and vibration of vocal chords
• Categorical perception


  Sounds on a continuum are perceived as belonging to distinct categories
• Categorical perception


  • Between category 2. Within category 3. Control
• Categorical perception is not language specific, non-humans can display it
• Phonemes


  Units of speech sounds
• Babbling


  Repetitive use of syllables, 6-15 months, universal
• Discontinuity Hypothesis


  No relation between babbling and later language development
• Continuity Hypothesis


  Babbling is a precursor to language development
• Isolated words


  Less than 10% of infant-directed speech consists of isolated words
• Statistical learning


  Infants can discriminate familiar from novel words based on transitional probabilities between syllables
• Syntax-like constructions


  Infants can learn words in a structured sequence
• Semantic development


  Meanings of words can be inferred from syntactic context
• Lexical spurt


  Rapid growth in vocabulary size, not observed systematically
• Whole-object bias


  Words refer to objects, not object parts
• Mutual exclusivity


  If an infant knows the name of an object, a novel word must mean something else
• Prosody


  The rhythm, stress, and intonation of speech, rather than the actual words being spoken.
• Utero


  Within the womb.
• When do babies respond to auditory stimuli in Utero?

  25-29 weeks
• What is a low pass filter?

  Dampens frequencies above 1000Hz