Infants’ speech perception ability
heir ability to devote attention to the prosodic and phonetic regularities of speech—develops tremendously in the first year as infants move from detecting larger patterns, such as rhythm, to detecting smaller patterns, such as combinations of specific sounds.
prosodic characteristics of speech
include the frequency, or pitch, of he duration, or length, of sounds; and the intensity, or loudness, of sounds.
- Combinations of these prosodic characteristics produce distinguishable stress and intonation patterns that infants can detect.
Stress
prominence placed on certain syllables of multisyllabic words.
Intonation
the prominence placed on certain syllables, but it also applies to entire phrases and sentences. F
By age 9 months, infants learning English prefer to listen to words
containing strong–weak stress patterns
How do infants use prosodic regularities to segment the speech stream?
phonetic details of speech include
phonemes, or speech sounds, and combina-tions of phonemes.
According to Stager and Werker, infants who are not yet learning words devote much attention to….
and older children concentrate their efforts on…
Categorical perception
allows listeners to distinguish between phonemes so they can quickly and efficiently process incoming speech by ignoring those variations that are non-essential or nonmeaningful in their language.
Detection of Nonnative Phonetic Differences. Infants
perceptual narrowing
infants start to focus more on perceptual differences that are relevant to them (such as the difference between two native phonemes) and focus less on perceptual differences that are not relevant to them, or that they encounter less often (such as the difference between two nonnative phonemes),
Detection of Phonotactic Regularities.
Categorical Perception of Speech
allophones
Variations of sounds in the same category
–lophones of a phoneme are measurably different from one another (such as in the amount of aspiration they contain), but they do not signal a difference in meaning between two words, as phonemes do.
voice onset time
is the interval between the release of a stop consonant (e.g., p, b, t, d) and the onset of vocal cord vibrations.
By age 4 months, infants can distinguish between
purposeful and accidental actions, and they appear to focus on the intentions underlying actions rather than the physical details of the actions
Over the first year, infants learn to view human actions as
goal-directed, mean-ing they pay attention to the outcomes and objects to which humans direct their actions rather than to other superficial perceptual properties of the event. F
Infants’ awareness of movement and understanding of the goals underlying actions are important precursors for language development because
once they understand the intentions behind actions, they, too, can engage in intentional communication by pointing, gesturing, and eventually using language.
Catogory formation
the idea that object category formation is
hierarchical and includes three levels:
superordinate level
subordinate level
basic level
infants use two types of categories at each level of the hierarchy:
-ceptual categories and conceptual categories