Topic 10: Early Speech Perception

Question 1

What is developmental psycholinguistics?

Answer 1

The study of the underlying cognitive processes involved in word learning and language acquisition.

Question 2

What are phonemes and prosody?

Answer 2

Phonemes – smallest unit of sound that is meaningful in native language
Prosody - speech qualities (irony, mood), rhythm and rate of syllables

Question 3

At what age is the auditory system functional? and how is this measured

Answer 3

Around 24 weeks foetus will respond to auditory stimulation measured by increase in heartrate or shift of position.

Question 4

What is the auditory environment like inside the womb?

Answer 4

▪ noisy environment
▪ external sounds are ‘muffled’
▪ lower frequency of speech
▪ maternal voice is loud, salient – but unintelligible & dissimilar to ‘outside’
* cannot detect phonemes but rather the prosody of language

Question 5

What tools/ methods are used in fetal research?

Answer 5

fetal ultrasound or electrocardiogram (prone to distortion) Or, fetal magnetocardiography – relies on magnetic field and is more precise

Question 6

Study on fetal familiarity of mother’s use of native language (Minai et al, 2017)

Answer 6

Using magnetocardiography
they measured the consistency of fetal heartrate when reading a passage in english-english or english- japanese. Results show less consistency when novel language is spoken, suggesting familiarity to native language.

Question 7

What are neonates?

Answer 7

A newborn child (less than 4 weeks old)

Question 8

How can we measure preferences in neonates?

Answer 8

By monitoring rates of non-nutritive sucking or by assessing them using the headturn preference procedure.

Question 9

What auditory preferences have neonates shown to have through non nutritive sucking research?

Answer 9

Human voice > synthetic sounds
maternal voice > male voice
maternal language > non native

Question 10

De Caspar & Spence (1986) Dr. Suess trans natal learning.

Answer 10

In later stages of pregnancy mothers read a Dr.Suess book consistenly aloud. After birth neonates showed preference for familiar Dr, Suess passage suggesting they were learning the rhythm of language in utero.

Question 11

What is perceptual learning?

Answer 11

long-lasting changes in (auditory) perception that arise from experience or practice. e.g. discrimination between speech sounds of different languages.

Question 12

Study on neonatal discimination between different languages.(Nazzi et al., 1998)

Answer 12

French neonates non-nutritive sucking rates were measured in response to non native langauge being spoken. Initially higher sucking rates for english, then initially higher rates for japanese but not dutch. Dutch and english have similar timing properties whereas japanese has a different rhythmic structure. So by 2 mths infants are able to discriminate between langauges.

Question 13

How do infants segment speech and find the
fundamental units in speech streams?

Answer 13

Categorical Perception: a perceptual phenomenon whereby events (e.g., sounds, colours) that lie along a continuum are perceived as belonging to one category or another.
So infants categorise phonemes into groups that help them to understand words and sentences.

Question 14

How do we have stable categories of speech sounds? e.g. pa-ba

Answer 14

speech sounds are on a physical continuum, most of us place the phoneme ‘boundary’ around the same place on this continuum

Question 15

Study of infants ability to extract perceptual categories from speech sounds (Eimas et al. 1972)

Answer 15

1-4mths old infants given continuous speech stream (ba-ba-ba) that merges into another syllable (da). Non-nutritive sucking rate increased much more when new syllable introduced compared to control group. Suggests infants can discriminate across phoneme boundaries.

Question 16

How do we know that categorisation is a general property of audition?

Answer 16

Chinchillas are very good at categorical perception of speech so it is not unique to humans. Categorisation is a general property of audition that captures the discontinuity in sounds.

Question 17

How do we know that categorisation is a general property of audition?

Answer 17

Categorisation captures the discontinuity in sounds. Chinchillas are very good at categorical perception of speech so it is not unique to humans. Therefore is a general property of audition.

Question 18

What is the Headturn Preference procedure and what can they show?

Answer 18

A method for detecting preferences (sounds, words, or sentences) in infants.
They can show discrimination of a change within a continuous sound stream e.g. /da-da-da-ba-ba-ba/.
And after training (habituation) to one sound (word or sentence) they can test dishabituation with a new sound

Question 19

Study: Infants ability to discriminate speech sounds of their native language and non-native languages (Werker & Tees, 1984)

Answer 19

Used a modified headturn procedure to measure American infants ability to percieve syllabic changes in native language and Hindi or Sallish.
Younger infants at 6-8 mths (80-90%) perceived both contrasts whereas fewer older infants at 10-12 mths (10-20%) perceived non-native contrasts.
Suggesting a big decline in distinguishing sounds from non-native languages through development.

Question 20

when do infants become more sensitive to the sounds of their native language? study (kuhl et al., 2006)

Answer 20

(kuhl et al., 2006) conducted an experiment with american and japanese infants on their ability to distinguish between r and l sounds (sounds that are ambigious in japanese). They found found that at 6-8 months infants from both countries have a similar level of ability but by 10-12 months american infants were far better at recognising the distinction and the japanese infants much worse. Suggesting USA infants are discriminating between the two sounds because they hear the words more freequently.

Question 21

Two types of statistics available from speech:

Answer 21

1. Distributional probability. Infants can capture how often some phonemes and syllables ‘show up’ in their native language.
2. Transitional probability of syllables that co-occur often together. Infants can capture what speech sounds/syllables are likely to be heard together in combination.

Question 22

What social factors help an infant learn langauge?

Answer 22

Child-directed speech (motherese) adults/carers use this when talking to children e.g. fewer words,
higher pitch (speech register), slower/ more pauses, more
repetition, exaggerated intonation patterns
Talking with others - helps orient the attention of infants e.g eye gaze, joint attention.

Question 23

Do infants actually need people to learn speech contrasts? study (kuhl, Tsao & Liu, 2003)

Answer 23

Attemped to teach mandarin to USA infants (10-12mths) either by live exposure to mandarin speaker or by TV exposure to mandarin speaking.
Only ‘live’ exposure to Mandarin (from a real person) enabled USA infants to discriminate the Mandarin contrasts when later tested.
Suggesting that language development is a combination of picking up the statistics of speech as well as the social environment.