Speech perception Flashcards
When a fetus can perceive environmental sounds
7 months of gestation
Fetuses only perceives ___low/high frequencies
Low (below 400Hz)
Higher frequencies speech (above 1000Hz) contains the most …
Acoustic information about segments (phones)
Fetuses receive more ____ information
Prosadic
What happens when a consonant is released
The articulators restricting airflow come apart.
Aspiration
Brief moment in which the vowel is not voiced after a voiceless stop
Voice onset time (VOT)
Period of time between the release of the stop and the onset of voicing (silence)
A VOT of 25 ms means…
Voicing begins 25 seconds after the stop is released
A VOT of more than ___ ms yields aspiration in English
25
A VOT of 0 means …
Voicing begins simultaneously with the release of the stop, creating a plain consonant (neither aspirated nor voiced)
A negative VOT means…
The voicing begins before the stop is released : the consonant AND the vowel are voiced
VOT boundary between voiced /b/ and voiceless /p/ in English
+25 ms
3 conditions of the VOT experiment on infants
1a. /ba/ vs /ba/ (VOT of -20 vs 0); voiced
1b. /pa/ vs /pa/ (VOT of +60 vs +80); aspirated
2. /ba/ vs /pa/ (VOT +20 vs +40); different
Steps of the VOT experiment
- First sound
- Habituation (HAS decreases)
- Second sound
- If the second sound is perceived as different, suck rate would increase (dehabituation)
Results of the VOT experiment
Even if all the pair of sounds only differed from 20ms, the infants heard only the difference between different categories present in adults’ grammar (/b/ vs /p/)
Categorical perception
Infants hear sounds categorically
True or false ? Infants with a native language with a different VOT value as English could perceive the English voiced/voiceless categories
True
True or false ? Infants with English as their native language could distinguish Spanish voiced vs plain sounds
False
American infants may distinguish Spanish voiced vs plain sounds if the acoustic difference is ___
Larger (70-80 ms)
Spanish VOT boundary
-5 ms (contrast voiced vs voiceless is more defined), harder to produce but not perceive
Until __ months, babies perceive non-native phonemic contrasts almost perfectly
6
Drop in nonnative contrasts perception performance
10 months old : 50% lost
1 year old : below 20%, almost as poor as adults
Age at which a baby’s ability to discriminate sounds is limited to the native language
1 year old
Maintenance-loss view
Idea that the neural structures used in the brain to respond to nonnative sound contrasts become inactive
Perceptual assimilation
Idea that our perceptual system is reorganized so that sounds that are not phonetically similar to native sounds are not even heard as linguistic sounds, while sounds that are similar to native sounds are assimilated to familiar sounds.
3 components of prosody
pitch, rythm, pauses
Babies of __ months know that pauses occur between rather than within clauses (subject+predicate)
7
Babies at __ months prefer IDS with pauses between rather than within phrases
9
Babies use ___ to find units in language
Pauses
From __ to 9 months, babies begin to break down units into smaller ones (from clause to phrase)
6
Prosodic bootstrapping
Babies notice patterns in the prosody of their language such as pause locations
____ create rhythm in language
Syllables
Syllables are defined as peaks of _____
Sonority
Nucleus of a syllable
Vowel
Rime
Nucleus + coda
A syllable with ____ stress usually indicates a word boundary
Primary
Age at which babies can segment speech into bisyllabic units with primary stress
7 to 9 months old (12 to 16 for French)
Phonotactics
Constraints on which speech sounds can occur next to each other in a syllable or a word
Transitional probabilities
Probability of 2 syllables to co-occur in a word (high transitional probability = syllables can probably occur together in a word)
9 months old infants prefer to listen nonword sequences contaning…
Possible and highly likley phonotactic patterns
Babies listen longer to words presented in the midst of ____poor/good phonotactic cues
Good
Babies assume word boundaries where __low/high transitional probability is detected
Low
In an experiment, babies heard strings of made-up words, then were presented with parts of these words (ex. pabiku and tibudo, then bikutibu). How did the babies react ?
They were surprised when they heard the part-words
8 months old can identify plausible word units when there is high _____ _____ between syllables
Transitional probabilities
After hearing ABA words (ga ti ga) and ABB words (ga ti ti), and then heard a different word of the same or opposite pattern, babies listened longer to the ____
different patterned word
Conclusion of the ABA/ABB study
Children can track the frequencies of abstract structures (even without using transitional probabilities)
