1Psych 56L/ Ling 51:Acquisition of LanguageLecture 7Phonological Development IIAnnouncementsIPA sound chart available on the class webpage (can use formidterm and homework)Homework 1 due today, by the end of classMistake from last lecture:The IPA for the English “r” sound is written ® (not r)Additional information not included in last lecture:The IPA for the English flapping consonant sound (heard in“water” and “butter”) is written RPrelinguistic “Speech” ProductionStages of Prespeech Vocal DevelopmentNewborns make biologically-related sounds: reflexive crying,burping, breathing, suckingHelpful: infants’ vocal cords vibrate & airflow through the vocalapparatus is stopped and started2Stages of Prespeech Vocal DevelopmentAround 6-8 weeks: infants start cooing (sounds that result frombeing happy).First coos sound like one long vowel - but over many months,they acquire a variety of different vowel sounds.Stages of Prespeech Vocal DevelopmentAround 16-30 weeks: vocal play. Infants use a variety ofdifferent consonant-like and vowel-like sounds. At the end ofthis stage, infants form long combinations of the sounds(marginal babbling).Recognizable vowel sounds heard at the beginning, whilerecognizable consonant sounds (usually velars like k/g) areusually heard around 2-3 months. Recognizable consonantsounds occurring near the front of the mouth (n/m/p/b/d) comein around 6 months of age.Stages of Prespeech Vocal DevelopmentAround 6-9 months: canonical/reduplicated babbling, with actualsyllables in the sounds produced (ex: [dadada]). Thesesyllables are often repeated in a row.Social aspect: babies don’t give any indication that they’rebabbling to communicate. They babble in the car and theircrib, showing no sign that they expect any reply.Note: even deaf infants babble, but they tend to producemarginal babbling instead of canonical babbling.Stages of Prespeech Vocal DevelopmentAfter canonical babbling: nonreduplicated/variegated babbling,with non-repetitive syllables and more variety in consonantand vowel sounds. Infants also incorporate prosody (therhythm of the language) into their babbling, which makes itsound much more like they’re trying to talk. However, the“words” in this kind of babbling are usually only 1 or 2syllables.3Stages of Prespeech Vocal Development0 weeks reflexive crying, biological-basedsounds4 weeks cooing16 weeks vocal play begins36 weeks reduplicated/canonical babbling48 weeksnonreduplicated babblingFirst WordIs all babbling the same?Besides the differences between the vocal babbling of deafchildren and non-deaf children, babies’ babbling is alsoinfluenced by the language they hear.How do we know?(1) Test competent native speakers.Record the babbling of babies who are learning to speakdifferent languages (ex: French, Arabic, Chinese). Seeif native speakers can identify which baby’s babble isfrom their language (ex: asking French mothers tochoose between Arabic babble and French babble asFrench.)De Boysson-Bardies, Sagart, and Durand (1984):recordings of 8-month-olds can be recognized bylanguage.Is all babbling the same?Besides the differences between the vocal babbling of deafchildren and non-deaf children, babies’ babbling is alsoinfluences by the language they hear.How do we know?(2) See if babbling features accord with language featuresDetermine which vowels and consonants appear inbabbling, and how frequently they appear. Compare totarget language’s vowels and consonants. (Can besubtle, though.)Ex: Japanese & French words contain more nasal soundsthan Swedish and English words; Japanese & Swedishbabbles contain more nasal sounds than Swedish &English babbles.Processes underlying speech sound developmentThree main factorsPhysical growth & development of the vocal tractDevelopment of brain & other neurological structuresresponsible for vocalizationExperience4Processes underlying speech sound developmentPhysical growth & development of the vocal tractA newborn’s vocal tract is smaller & shaped differentlyfrom an adult’s. (Ex: The tongue fills the entire mouth,limiting range of motion.)As the facial skeleton grows, the tongue gets more room.This happens during the vocal play stage, and theexploration of this new vocal freedom may be the causeof the vocal play itself.Processes underlying speech sound developmentDevelopment of brain & other neurological structuresresponsible for vocalizationLater neurological developments in higher brainstructures correlate with developments in vocalization.Ex: Onset of cooing at 6-8 weeks coincides withdevelopment of limbic system (associated withexpression of emotion in both humans and otheranimals).Maturation of areas in the motor cortex may be requiredfor the onset of canonical babbling.Processes underlying speech sound developmentExperienceExperience 1: Hearing the speech adults produce(influences the sounds children choose to babble andprosodic character of later babbling)Experience 2: Hearing their own vocal output (allows forcalibration - matching what they produce to what theyhear). Absence of auditory feedback may explain whydeaf infants produce less elaborate vocal play thanhearing infants, and reach the canonical babbling stagelater.Prelinguistic Speech Perception5Infants’ HearingInfants’ hearing is not quite as sensitive as adults’ - but they c anhear quite well and remember what they hear.Ex: Fetuses 38 weeks oldA loudspeaker was placed 10cm away from the mother’sabdomen. The heart rate of the fetus went up in response tohearing a recording of the mother’s voice, as compared tohearing a recording of a stranger’s voice.Infants’ HearingInfants’ hearing is not quite as sensitive as adults’ - but they c anhear quite well and remember what they hear.Ex: newbornsPregnant women read a passage out loud every day for the last6 weeks of their pregnancy. Their newborns showed apreference for that passage over other passages read by theirmothers.Studying Infant Speech PerceptionResearchers use indirect measurement techniques.High Amplitude Sucking (HAS)Infants are awake and in a quietly alert state. They are placedin a comfortable reclined chair and offered a sterilized pacifierthat is connected to a pressure transducer and a computer viaa piece of rubber tubing. Once the infant has begun sucking,the computer measures the infant’s average sucking amplitude(strength of the sucks).Studying Infant Speech PerceptionResearchers use indirect measurement